<PAGE>

AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON APRIL 23, 1998
                                   Registration Statement No. 33-_______________
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------



                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM S-8
                             Registration Statement
                                    Under The
                             Securities Act Of 1933

         --------------------------------------------------------------



                               AMEREN CORPORATION
             (Exact name of registrant as specified in its charter)

         State of Missouri                                   43-1723446
  (State or other jurisdiction                             (IRS Employer
of incorporation or organization)                        Identification No.)


                              1901 Chouteau Avenue
                            St. Louis, Missouri 63103
          (Address, including zip code, of principal executive offices)

         --------------------------------------------------------------


                               AMEREN CORPORATION
                        LONG-TERM INCENTIVE PLAN OF 1998
                            (Full title of the plan)


                DONALD E. BRANDT, Senior Vice President, Finance
                          JAMES C. THOMPSON, Secretary
                 1901 Chouteau Avenue, St. Louis, Missouri 63103
                                 (314) 621-3222
(Names, address and telephone number, including area code,of agents for service)

<TABLE>
<CAPTION>

                         CALCULATION OF REGISTRATION FEE

=============================================================================================================================
                                                                    Proposed            Proposed
           Title of securities                    Amount             maximum             maximum             Amount of
             to be registered                     to be          offering price         aggregate          registration
                                                Registered          per unit*        offering price             fee
-----------------------------------------------------------------------------------------------------------------------------
<S>                                        <C>                    <C>               <C>                     <C>   
 Common Stock, $.01 par value, including     4,000,000 shares       $41.125           $164,500,000            $49,848
              related rights
=============================================================================================================================

</TABLE>


*   Calculated in accordance with Rule 457(h) on the basis of the average of the
    high and low prices of Ameren  Corporation  Common  Stock as reported on the
    New York Stock Exchange Composite Tape on April 18, 1998.


<PAGE>



                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

         The following  documents,  previously  filed with the Commission by the
Registrant (File No. 1-14756)  pursuant to the Securities  Exchange Act of 1934,
as amended, are incorporated by reference in this Registration Statement:

         1. The  Registrants's  Annual  Report on Form  10-K for the year  ended
December 31, 1997.

         2. The  Registrant's  Current  Reports on Form 8-K dated  December  31,
1997, January 20, 1998 and March 13, 1998.

         3. The  Registrant's  Registration  Statement on  Form S-4 (Reg. No.33-
64165), filed  November 13, 1995,  which  includes  a description  of the Common
Stock of the Registrant.

All documents  subsequently filed by the Registrant  pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, prior to
the filing of a  post-effective  amendment  which  indicates that all securities
offered  have been  sold or which  deregisters  all  securities  then  remaining
unsold,  shall be deemed to be incorporated by reference herein and to be a part
hereof from the date of the filing of such documents.

Item 4.  Description of Securities

         Not Applicable.

Item 5.  Interests of Named Experts and Counsel

         William E, Jaudes,  Esq.,  Vice  President  and General  Counsel of the
Registrant,  will  pass upon the  legality  of the  shares  of Common  Stock and
related rights of the Registrant to be issued under the Plan. Mr. Jaudes will be
eligible to receive awards under the Plan.

Item 6.  Indemnification of Directors and Officers

         Article IV of the Registrant's By-Laws,  consistent with the applicable
provisions of the Missouri  General and Business  Corporation Law (the "MGBCL"),
provides for indemnification of directors and officers. These provisions provide
that any person shall be indemnified for expenses and  liabilities  imposed upon
such person in  connection  with any  threatened,  pending or completed  action,
suit, or proceeding,  whether civil, criminal,  administrative or investigative,
other than an action by or in the right of the Registrant, by reason of the fact
that  such  person  is or was a  director,  officer,  employee  or  agent of the
Registrant, or is or was serving at the request of the Registrant as a director,
officer,

                                     II - 1

<PAGE>



employee or agent of another corporation,  partnership,  joint venture, trust or
other enterprise,  against expenses, including attorneys' fees, judgments, fines
and amounts paid in settlement  actually and reasonably  incurred by such person
in connection with such action,  suit or proceeding if such person acted in good
faith and in a manner such person reasonably believed to be in or not opposed to
the best interests of the  Registrant,  and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful.

         In a  proceeding  brought  by or in the  right  of the  Registrant,  no
indemnification  shall be made with  respect to any claim as to which an officer
or director  has been  adjudged to have been  liable to  Registrant,  unless the
court  determines  that such a person  is  reasonably  and  fairly  entitled  to
indemnification  for  expenses.  However,  no  indemnification  shall be made in
respect of any claim,  issue or matter as to which such  person  shall have been
adjudged to be liable for  negligence or misconduct  in the  performance  of his
duty to the Registrant unless and only to the extent that the court in which the
action  or suit was  brought  determines  upon  application  that,  despite  the
adjudication of liability and in view of all the  circumstances of the case, the
person is fairly and  reasonably  entitled to indemnity for such expenses  which
the court shall deem proper.

         The By-laws,  consistent  with the applicable  provisions of the MGBCL,
provide  that  indemnification  shall  be  made  by  the  Registrant  only  if a
determination  has been made by a majority vote of a quorum of the disinterested
directors or by the  shareholders  or by  independent  legal  counsel,  that the
director or officer met the  required  standard of conduct.  The  Registrant  is
authorized to purchase  liability  insurance on behalf of an officer or director
whether or not the Registrant  would  otherwise have the power to indemnify such
person.

         The By-laws,  consistent  with the applicable  provisions of the MGBCL,
further provide that, in addition to the indemnities  described in the preceding
paragraphs,  the Registrant will further indemnify its officers and directors to
the maximum extent permitted by law, provided that no indemnity may be given for
conduct that is adjudged to be knowingly fraudulent,  deliberately dishonest, or
willful misconduct.

Item 7.  Exemptions from Registration Claimed

         Not Applicable.

Item 8.  Exhibits

         Exhibit No.

           4.1        Restated  Articles  of  Incorporation  of  the  Registrant
                      (incorporated  by  reference to  Annex F  of the  Form S-4
                      Registration  Statement  of  the Registrant,  Reg. No. 33-
                      64165).

           4.2        By-Laws of  the  Registrant (incororated  by  reference to
                      Exhibit 3(ii) of the 1997 Form 10-K).

                                     II - 2

<PAGE>




           5          Opinion  of  William E. Jaudes  as  to the legality of the
                      securities being issued.

          23.1        Consent of Price Waterhouse LLP.

          23.2        Consent of Arthur Andersen LLP.

          23.3        Consent of William E. Jaudes (included in Exhibit 5).

          24          Powers of Attorney.

Item 9.  Undertakings

  (a)     The undersigned Registrant hereby undertakes:

          (1) To file,  during  any  period  in which  offers or sales are being
made, a post-effective amendment to this registration statement:

                  (i) To include any  prospectus required by Section 10(a)(3) of
the Securities Act of 1933;

                  (ii) To reflect in the  prospectus any facts or events arising
after the  effective  date of the  registration  statement  (or the most  recent
post-effective  amendment  thereof)  which,  individually  or in the  aggregate,
represent a fundamental  change in the information set forth in the registration
statement.  Notwithstanding the foregoing, any increase or decrease in volume of
securities  offered (if the total dollar value of  securities  offered would not
exceed that which was  registered) and any deviation from the low or high end of
the estimated  maximum offering range may be reflected in the form of prospectus
filed with the  Commission  pursuant  to Rule 424(b) if, in the  aggregate,  the
changes in volume and price  represent  no more than a 20% change in the maximum
aggregate  offering price set forth in the  "Calculation  of  Registration  Fee"
table in the effective registration statement;

                  (iii) To include any material  information with respect to the
plan of distribution not previously  disclosed in the registration  statement or
any material change to such information in the registration statement;

Provided,  however, that paragraphs (a)(l)(i) and (a)(l)(ii) do not apply if the
registration statement is on Form S-3, Form S-8 or Form F-3, and the information
required to be included in a  post-effective  amendment by those  paragraphs  is
contained in periodic  reports filed with or furnished to the  Commission by the
Registrant  pursuant to Section 13 or Section 15(d) of the  Securities  Exchange
Act of 1934 that are incorporated by reference in this registration statement.

          (2) That,  for the  purpose of  determining  any  liability  under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration

                                     II - 3

<PAGE>



statement  relating to the securities  offered  therein and the offering of such
securities  at that time shall be deemed to be the  initial  bona fide  offering
thereof.

          (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

  (b) The  undersigned  Registrant  hereby  undertakes  that,  for  purposes  of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

  (c) Insofar as  indemnification  for liabilities  arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the  Registrant  pursuant  to the  provisions  referred  to in  Item  6 of  this
Registration  Statement,  or otherwise,  the Registrant has been advised that in
the opinion of the Securities and Exchange  Commission such  indemnification  is
against public policy as expressed in the Act and is, therefore,  unenforceable.
In the event that a claim for  indemnification  against such liabilities  (other
than the payment by the  Registrant of expenses  incurred or paid by a director,
officer or controlling person of the Registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered,  the Registrant will,
unless in the opinion of its counsel the matter has been settled by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification by it is against public policy as expressed in the Act and
will be governed by the final adjudication of such issue.


                                     II - 4

<PAGE>



                                   SIGNATURES


          The Registrant.  Pursuant to the requirements of the Securities Act of
1933, the Registrant certifies that it has reasonable grounds to believe that it
meets all of the  requirements  for filing on Form S-8 and has duly  caused this
Registration  Statement to be signed on its behalf by the undersigned  thereunto
duly authorized, in the City of St. Louis, State of Missouri, on the 23rd day of
April, 1998.




                                                AMEREN CORPORATION


                                             By /s/ Donald E. Brandt
                                                ---------------------
                                                 DONALD E. BRANDT
                                          Senior Vice President, Finance


         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has  been  signed  by  the  following  persons  in  the
capacities and on the date above indicated.


       Signature                                     Title



/s/ Charles W. Mueller*                    Chairman, President and Chief
-----------------------                    Executive Officer and Director
    CHARLES W. MUELLER                     (Principal Executive Officer)


/s/ Donald E. Brandt                       Senior Vice President, Finance
--------------------                          (Principal Financial and
    DONALD E. BRANDT                             Accounting Officer)


/s/ Clifford L. Greenwalt*                          Director
--------------------------
    CLIFFORD L. GREENWALT



/s/ William E. Cornelius*                           Director
-------------------------
    WILLIAM E. CORNELIUS



/s/ Thomas A. Hays*                                 Director
-------------------
    THOMAS A. HAYS

                                     II - 5

<PAGE>





/s/ Richard A. Liddy*                               Director
---------------------
    RICHARD A. LIDDY



                                                    Director
---------------------
    GORDAN R. LOHMAN



/s/ Richard A. Lumpkin*                             Director
-----------------------
    RICHARD A. LUMPKIN



/s/ John Peters MacCarthy*                          Director
--------------------------
    JOHN PETERS MACCARTHY


                                                    Director
------------------------
    HANNE M. MERRIMAN


/s/ Paul L. Miller, Jr.*                            Director
------------------------
    PAUL L. MILLER, JR.



/s/ Robert H. Quenon*                               Director
---------------------
    ROBERT H. QUENON



/s/ Harvey Saligman*                                Director
--------------------
    HARVEY SALIGMAN



/s/ Charles J. Schukai*                             Director
-----------------------
    CHARLES J. SCHUKAI



/s/ Janet McAfee Weakley*                           Director
-------------------------
    JANET MCAFEE WEAKLEY





                                     II - 6

<PAGE>






                                                   Director
-----------------------
    JAMES W. WOGSLAND




                                                     *By  /s/ James C. Thompson
                                                           ---------------------
                                                              JAMES C. THOMPSON
                                                               Attorney-In-Fact

                                     II - 7

<PAGE>


[AMEREN CORPORATION LETTERHEAD]


                                 April 23, 1998                        EXHIBIT 5

Ameren Corporation
1901 Chouteau Avenue
St. Louis, Missouri  63103

       Re:   Registration Statement on Form S-8 Relating to 4,000,000  Shares of
             Common Stock, Including Related Rights

Ladies and Gentlemen:

       I have examined the Registration Statement on Form S-8 (the "Registration
Statement") filed by Ameren Corporation, a Missouri corporation (the "Company"),
with the Securities and Exchange Commission on April 23, 1998 in connection with
the  registration  under the  Securities  Act of 1933, as amended,  of 4,000,000
shares of the Common Stock,  $.01 par value per share,  including related rights
(the  "Common  Stock"),  of the Company to be offered  and sold  pursuant to the
Ameren Corporation Long-Term Incentive Plan of 1998 (the "Plan").

       As Vice President and General Counsel of the Company, I have examined the
Restated  Articles  of  Incorporation  and the By-laws of the  Company,  each as
amended to the date  hereof,  the  records of  corporate  proceedings  and other
actions taken by the Company in connection with the authorization,  issuance and
sale of the Common Stock and such other documents and materials as I have deemed
necessary or appropriate to enable me to deliver this opinion.

       Based upon the foregoing, I am of the opinion that:

       Subject  to (i) compliance  with  applicable  state securities laws, (ii)
approval of  the Plan by the Securities and Exchange Commission under the Public
Utility Holding Company Act  of 1935, and (iii) the filing and  effectiveness of
the  Registration  Statement  with the Securities and Exchange  Commission,  the
Common Stock,  when issued and sold in the manner described in the  Registration
Statement,  will be legally issued, fully paid and nonassessable.

       I hereby  consent  to the  filing of this  opinion  as an  exhibit to the
Registration Statement.

                                            Yours truly,


                                          /s/ William E. Jaudes
                                          ----------------------
                                             William E. Jaudes
                                             Vice President and General Counsel
                                             Ameren Corporation

                                     II - 8

<PAGE>

[PRICE WATERHOUSE LLP LETTERHEAD]

                                                                    EXHIBIT 23.1


                       CONSENT OF INDEPENDENT ACCOUNTANTS


       We hereby consent to the  incorporation by reference in this Registration
Statement on Form S-8 of our report  dated  February 5, 1998,  which  appears on
page 17 of the 1997 Annual Report to Shareholders of Ameren  Corporation,  which
is incorporated by reference in Ameren  Corporation's Annual Report on Form 10-K
for the year ended  December 31, 1997. We also consent to the  incorporation  by
reference  in this  Registration  Statement  on  Form  S-8 of our  report  dated
December  17,  1997,  which  appears  on page 9 of  Exhibit  99-2 to the  Ameren
Corporation  Current Report on Form 8-K dated December 31, 1997, with respect to
the supplemental  consolidated  financial statements of Ameren Corporation as of
December  31, 1996 and 1995 and for each of the three years in the period  ended
December 31, 1996, except as such Ameren Corporation financial statements relate
to Central Illinois Public Service Company and CIPSCO  Investment  Company.  The
Central Illinois Public Service Company and CIPSCO Investment  Company financial
statements were audited by another  independent  accountant.  We also consent to
the  incorporation by reference in the  Registration  Statement on Form S-4 (No.
33-64165) of Ameren  Corporation dated November 13, 1995 (the "Form S-4") of our
report  dated  February  1, 1996,  which  appears  on page 16 of Union  Electric
Company's 1995 Annual Report to Shareholders  which is incorporated by reference
in Union  Electric  Company's  Annual  Report  on Form  10-K for the year  ended
December 31, 1995, which Form 10-K is incorporated by reference in the Form S-4.
The Form S-4 is incorporated by reference in this Registration Statement on Form
S-8.  We  also  consent  to the  application  of our  reports  to the  Financial
Statement  Schedules,  which  appear on page 10 of Ameren  Corporation's  Annual
Report on Form 10-K for the year ended  December  31,  1997 and page 12 of Union
Electric  Company's  Annual Report on Form 10-K for the year ended  December 31,
1995,  for each of the five years in the period ended  December  31, 1997,  when
such Schedules are read in conjunction with the financial statements referred to
in our reports dated February 5, 1998 and February 1, 1996.



/S/ Price Waterhouse LLP
-------------------------
    Price Waterhouse LLP
    St. Louis, Missouri
    April 23, 1998




                                     II - 9

<PAGE>

[ARTHUR ANDERSEN LLP LETTERHEAD]

                                                                    Exhibit 23.2


                               ARTHUR ANDERSEN LLP




                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS


         As   independent   public   accountants,   we  hereby  consent  to  the
incorporation by reference in this  Registration  Statement of our reports dated
January 31,  1997,  January 26, 1996,  and January 27, 1995,  included in CIPSCO
Incorporated's  Form 10-K for the years ended December 31, 1996,  1995 and 1994,
respectively,  and to all  references to our Firm included in this  Registration
Statement.



                                                 /S/ Arthur Andersen LLP
                                                 ------------------------
                                                     ARTHUR ANDERSEN LLP

Chicago, Illinois
April 23, 1998

                                     II - 10

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Charles W.
Mueller hereby  appoints  Donald E. Brandt and/or James C. Thompson the true and
lawful  attorneys-in-fact  of the  undersigned,  for and in the name,  place and
stead of the undersigned, to affix the name of the undersigned as a Director and
as Chairman of The Board,  President,  and Chief  Executive  Officer,  of Ameren
Corporation to a  Registration  Statement(s)  and any  amendments  thereto to be
filed with the  Securities and Exchange  Commission  under the Securities Act of
1933,  covering the issue of Common Stock under the  dividend  reinvestment  and
stock purchase plan,  stock  incentive  plan, and savings  investment  plans, as
authorized  by the Company's  Board of Directors on December 17, 1997,  and, for
the  performance of the same acts, each with power to appoint in their place and
stead  and  as  their  substitute,   one  or  more   attorneys-in-fact  for  the
undersigned,  with full power of revocation; hereby ratifying and confirming all
that said attorneys-in-fact may do by virtue hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.

                                              Charles W. Mueller      (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Charles W. Mueller,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                Barbara Lungwitz
                                                ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Donald E.
Brandt hereby appoints  Charles W. Mueller and/or James C. Thompson the true and
lawful  attorneys-in-fact  of the  undersigned,  for and in the name,  place and
stead of the undersigned,  to affix the name of the undersigned as the principal
financial  and  accounting  officer  of  Ameren  Corporation  to a  Registration
Statement(s)  and any  amendments  thereto to be filed with the  Securities  and
Exchange  Commission  under the  Securities  Act of 1933,  covering the issue of
Common Stock under the dividend  reinvestment  and stock  purchase  plan,  stock
incentive  plan, and savings  investment  plans,  as authorized by the Company's
Board of Directors on December 17, 1997,  and, for the  performance  of the same
acts,  each  with  power  to  appoint  in their  place  and  stead  and as their
substitute,  one or more attorneys-in-fact for the undersigned,  with full power
of revocation;  hereby ratifying and confirming all that said  attorneys-in-fact
may do by virtue hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                                  Donald E. Brandt    (L.S.)
                                                  --------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Donald E. Brandt, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                    Barbara Lungwitz
                                                    ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  William E.
Cornelius  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                              William E. Cornelius    (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared William E. Cornelius,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                   Barbara Lungwitz
                                                   ----------------


<PAGE>

                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned  Clifford L.
Greenwalt  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 31st day of December, 1997.
                                            Clifford L. Greenwalt    (L.S.)
                                            -------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally appeared Clifford L. Greenwalt,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                              Barbara Lungwitz
                                              ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Thomas A.
Hays hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James C.
Thompson the true and lawful  attorneys-in-fact  of the undersigned,  for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 20th day of December, 1997.
                                                Thomas A. Hays        (L.S.)
                                                ----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 20th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Thomas A. Hays, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                 Barbara Lungwitz
                                                 ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Richard A.
Liddy hereby appoints Charles W. Mueller and/or Donald E. Brandt and/or James C.
Thompson the true and lawful  attorneys-in-fact  of the undersigned,  for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                               Richard A. Liddy       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Richard A. Liddy, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                 Barbara Lungwitz
                                                 ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Richard A.
Lumpkin hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 31st day of December, 1997.
                                             Richard A. Lumpkin       (L.S.)
                                             -------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Richard A. Lumpkin,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                 Barbara Lungwitz
                                                 ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned  John Peters
MacCarthy  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                           John Peters MacCarthy      (L.S.)
                                           ---------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally appeared John Peters MacCarthy,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                             Barbara Lungwitz
                                             ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


               KNOW ALL MEN BY THESE PRESENTS:  That  the  undersigned  Paul  L.
Miller,  Jr. hereby  appoints Charles W. Mueller and/or Donald E. Brandt  and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the  name,  place  and  stead  of the  undersigned,  to  affix  the  name
of  the  undersigned as  a  Director of  Ameren  Corporation to  a  Registration
Statement(s)and any  amendments  thereto to be filed  with  the  Securities  and
Exchange  Commission  under the  Securities Act of 1933,  covering  the issue of
Common Stock  under  the dividend  reinvestment  and  stock purchase plan, stock
incentive plan, and savings  investment plans, as authorized  by  the  Company's
Board of Directors on December 17, 1997, and, for  the performance  of the  same
acts, each with  power to  appoint  in  their  place  and  stead  and  as  their
substitute, one or more attorneys-in-fact for the  undersigned,  with full power
of revocation; hereby ratifying and confirming all that  said  attorneys-in-fact
may do by  virtue hereof.
              IN WITNESS WHEREOF, the undersigned has hereunto set his hand  and
seal this 31st day of December, 1997.
                                              Paul L. Miller, Jr.     (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Paul L. Miller,  Jr.,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                               Barbara Lungwitz
                                               ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Robert H.
Quenon hereby  appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 24th day of December, 1997.
                                               Robert H. Quenon       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 24th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Robert H. Quenon, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                               Barbara Lungwitz
                                               ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW  ALL MEN BY  THESE  PRESENTS:  That  the  undersigned  Harvey
Saligman hereby appoints Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                               Harvey Saligman       (L.S.)
                                               ----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Harvey Saligman,  known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                               Barbara Lungwitz
                                               ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Charles J.
Schukai hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                              Charles J. Schukai     (L.S.)
                                              -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Charles J. Schukai,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                               Barbara Lungwitz
                                               ----------------

<PAGE>


                                                                     EXHIBIT 24

                                POWER OF ATTORNEY


              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned Janet McAfee
Weakley hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                               Janet M. Weakley       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Janet McAfee Weakley,
known to me to be the person  described in and who executed the foregoing  power
of attorney  and  acknowledged  to me that she executed the same as her free act
and deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.


                                                Kathleen D. O'Reilly
                                                --------------------
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 51631}]
{"company-data": {"conformed-name": "AMEREN CORP", "cik": "0001002910", "assigned-sic": "1000", "irs-number": "431723446", "state-of-incorporation": "MO", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-50793", "film-number": "98599372"}, "business-address": {"street1": "1901 CHOUTEAU AVE", "city": "ST LOUIS", "state": "MO", "zip": "63103", "phone": "3146213222"}, "mail-address": {"street1": "1901 CHOUTEAU AVE", "city": "ST LOUIS", "state": "MO", "zip": "63103"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON APRIL 23, 1998
                                   Registration Statement No. 33-_______________
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM S-8
                             Registration Statement
                                    Under The
                             Securities Act Of 1933

         --------------------------------------------------------------

                               AMEREN CORPORATION
             (Exact name of registrant as specified in its charter)

         State of Missouri                                   43-1723446
  (State or other jurisdiction                             (IRS Employer
of incorporation or organization)                        Identification No.)

                              1901 Chouteau Avenue
                            St. Louis, Missouri 63103
          (Address, including zip code, of principal executive offices)

         --------------------------------------------------------------

                               AMEREN CORPORATION
                        LONG-TERM INCENTIVE PLAN OF 1998
                            (Full title of the plan)

                DONALD E. BRANDT, Senior Vice President, Finance
                          JAMES C. THOMPSON, Secretary
                 1901 Chouteau Avenue, St. Louis, Missouri 63103
                                 (314) 621-3222
(Names, address and telephone number, including area code,of agents for service)
CALCULATION OF REGISTRATION FEE

=============================================================================================================================
                                                                    Proposed            Proposed
           Title of securities                    Amount             maximum             maximum             Amount of
             to be registered                     to be          offering price         aggregate          registration
                                                Registered          per unit*        offering price             fee
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.01 par value, including     4,000,000 shares       $41.125           $164,500,000            $49,848
              related rights
=============================================================================================================================
*   Calculated in accordance with Rule 457(h) on the basis of the average of the
    high and low prices of Ameren  Corporation  Common  Stock as reported on the
    New York Stock Exchange Composite Tape on April 18, 1998.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference

         The following  documents,  previously  filed with the Commission by the
Registrant (File No. 1-14756)  pursuant to the Securities  Exchange Act of 1934,
as amended, are incorporated by reference in this Registration Statement:

         1. The  Registrants's  Annual  Report on Form  10-K for the year  ended
December 31, 1997.

         2. The  Registrant's  Current  Reports on Form 8-K dated  December  31,
1997, January 20, 1998 and March 13, 1998.

         3. The  Registrant's  Registration  Statement on  Form S-4 (Reg. No.33-
64165), filed  November 13, 1995,  which  includes  a description  of the Common
Stock of the Registrant.

All documents  subsequently filed by the Registrant  pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, prior to
the filing of a  post-effective  amendment  which  indicates that all securities
offered  have been  sold or which  deregisters  all  securities  then  remaining
unsold,  shall be deemed to be incorporated by reference herein and to be a part
hereof from the date of the filing of such documents.

Item 4.  Description of Securities

         Not Applicable.

Item 5.  Interests of Named Experts and Counsel

         William E, Jaudes,  Esq.,  Vice  President  and General  Counsel of the
Registrant,  will  pass upon the  legality  of the  shares  of Common  Stock and
related rights of the Registrant to be issued under the Plan. Mr. Jaudes will be
eligible to receive awards under the Plan.

Item 6.  Indemnification of Directors and Officers

         Article IV of the Registrant's By-Laws,  consistent with the applicable
provisions of the Missouri  General and Business  Corporation Law (the "MGBCL"),
provides for indemnification of directors and officers. These provisions provide
that any person shall be indemnified for expenses and  liabilities  imposed upon
such person in  connection  with any  threatened,  pending or completed  action,
suit, or proceeding,  whether civil, criminal,  administrative or investigative,
other than an action by or in the right of the Registrant, by reason of the fact
that  such  person  is or was a  director,  officer,  employee  or  agent of the
Registrant, or is or was serving at the request of the Registrant as a director,
officer,

                                     II - 1
employee or agent of another corporation,  partnership,  joint venture, trust or
other enterprise,  against expenses, including attorneys' fees, judgments, fines
and amounts paid in settlement  actually and reasonably  incurred by such person
in connection with such action,  suit or proceeding if such person acted in good
faith and in a manner such person reasonably believed to be in or not opposed to
the best interests of the  Registrant,  and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful.

         In a  proceeding  brought  by or in the  right  of the  Registrant,  no
indemnification  shall be made with  respect to any claim as to which an officer
or director  has been  adjudged to have been  liable to  Registrant,  unless the
court  determines  that such a person  is  reasonably  and  fairly  entitled  to
indemnification  for  expenses.  However,  no  indemnification  shall be made in
respect of any claim,  issue or matter as to which such  person  shall have been
adjudged to be liable for  negligence or misconduct  in the  performance  of his
duty to the Registrant unless and only to the extent that the court in which the
action  or suit was  brought  determines  upon  application  that,  despite  the
adjudication of liability and in view of all the  circumstances of the case, the
person is fairly and  reasonably  entitled to indemnity for such expenses  which
the court shall deem proper.

         The By-laws,  consistent  with the applicable  provisions of the MGBCL,
provide  that  indemnification  shall  be  made  by  the  Registrant  only  if a
determination  has been made by a majority vote of a quorum of the disinterested
directors or by the  shareholders  or by  independent  legal  counsel,  that the
director or officer met the  required  standard of conduct.  The  Registrant  is
authorized to purchase  liability  insurance on behalf of an officer or director
whether or not the Registrant  would  otherwise have the power to indemnify such
person.

         The By-laws,  consistent  with the applicable  provisions of the MGBCL,
further provide that, in addition to the indemnities  described in the preceding
paragraphs,  the Registrant will further indemnify its officers and directors to
the maximum extent permitted by law, provided that no indemnity may be given for
conduct that is adjudged to be knowingly fraudulent,  deliberately dishonest, or
willful misconduct.

Item 7.  Exemptions from Registration Claimed

         Not Applicable.

Item 8.  Exhibits

         Exhibit No.

           4.1        Restated  Articles  of  Incorporation  of  the  Registrant
                      (incorporated  by  reference to  Annex F  of the  Form S-4
                      Registration  Statement  of  the Registrant,  Reg. No. 33-
                      64165).

           4.2        By-Laws of  the  Registrant (incororated  by  reference to
                      Exhibit 3(ii) of the 1997 Form 10-K).

                                     II - 2
5          Opinion  of  William E. Jaudes  as  to the legality of the
                      securities being issued.

          23.1        Consent of Price Waterhouse LLP.

          23.2        Consent of Arthur Andersen LLP.

          23.3        Consent of William E. Jaudes (included in Exhibit 5).

          24          Powers of Attorney.

Item 9.  Undertakings

  (a)     The undersigned Registrant hereby undertakes:

          (1) To file,  during  any  period  in which  offers or sales are being
made, a post-effective amendment to this registration statement:

                  (i) To include any  prospectus required by Section 10(a)(3) of
the Securities Act of 1933;

                  (ii) To reflect in the  prospectus any facts or events arising
after the  effective  date of the  registration  statement  (or the most  recent
post-effective  amendment  thereof)  which,  individually  or in the  aggregate,
represent a fundamental  change in the information set forth in the registration
statement.  Notwithstanding the foregoing, any increase or decrease in volume of
securities  offered (if the total dollar value of  securities  offered would not
exceed that which was  registered) and any deviation from the low or high end of
the estimated  maximum offering range may be reflected in the form of prospectus
filed with the  Commission  pursuant  to Rule 424(b) if, in the  aggregate,  the
changes in volume and price  represent  no more than a 20% change in the maximum
aggregate  offering price set forth in the  "Calculation  of  Registration  Fee"
table in the effective registration statement;

                  (iii) To include any material  information with respect to the
plan of distribution not previously  disclosed in the registration  statement or
any material change to such information in the registration statement;

Provided,  however, that paragraphs (a)(l)(i) and (a)(l)(ii) do not apply if the
registration statement is on Form S-3, Form S-8 or Form F-3, and the information
required to be included in a  post-effective  amendment by those  paragraphs  is
contained in periodic  reports filed with or furnished to the  Commission by the
Registrant  pursuant to Section 13 or Section 15(d) of the  Securities  Exchange
Act of 1934 that are incorporated by reference in this registration statement.

          (2) That,  for the  purpose of  determining  any  liability  under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration

                                     II - 3
statement  relating to the securities  offered  therein and the offering of such
securities  at that time shall be deemed to be the  initial  bona fide  offering
thereof.

          (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

  (b) The  undersigned  Registrant  hereby  undertakes  that,  for  purposes  of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Securities  Exchange  act of 1934  (and,  where  applicable,  each  filing of an
employee  benefit  plan's  annual  report  pursuant  to  Section  15(d)  of  the
Securities  Exchange  Act of 1934)  that is  incorporated  by  reference  in the
registration  statement  shall  be  deemed  to be a new  registration  statement
relating to the securities offered therein,  and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

  (c) Insofar as  indemnification  for liabilities  arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the  Registrant  pursuant  to the  provisions  referred  to in  Item  6 of  this
Registration  Statement,  or otherwise,  the Registrant has been advised that in
the opinion of the Securities and Exchange  Commission such  indemnification  is
against public policy as expressed in the Act and is, therefore,  unenforceable.
In the event that a claim for  indemnification  against such liabilities  (other
than the payment by the  Registrant of expenses  incurred or paid by a director,
officer or controlling person of the Registrant in the successful defense of any
action, suit or proceeding) is asserted by such director, officer or controlling
person in connection with the securities being registered,  the Registrant will,
unless in the opinion of its counsel the matter has been settled by  controlling
precedent,  submit to a court of appropriate  jurisdiction  the question whether
such  indemnification by it is against public policy as expressed in the Act and
will be governed by the final adjudication of such issue.

                                     II - 4
SIGNATURES

          The Registrant.  Pursuant to the requirements of the Securities Act of
1933, the Registrant certifies that it has reasonable grounds to believe that it
meets all of the  requirements  for filing on Form S-8 and has duly  caused this
Registration  Statement to be signed on its behalf by the undersigned  thereunto
duly authorized, in the City of St. Louis, State of Missouri, on the 23rd day of
April, 1998.

                                                AMEREN CORPORATION

                                             By /s/ Donald E. Brandt
                                                ---------------------
                                                 DONALD E. BRANDT
                                          Senior Vice President, Finance

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has  been  signed  by  the  following  persons  in  the
capacities and on the date above indicated.

       Signature                                     Title

/s/ Charles W. Mueller*                    Chairman, President and Chief
-----------------------                    Executive Officer and Director
    CHARLES W. MUELLER                     (Principal Executive Officer)

/s/ Donald E. Brandt                       Senior Vice President, Finance
--------------------                          (Principal Financial and
    DONALD E. BRANDT                             Accounting Officer)

/s/ Clifford L. Greenwalt*                          Director
--------------------------
    CLIFFORD L. GREENWALT

/s/ William E. Cornelius*                           Director
-------------------------
    WILLIAM E. CORNELIUS

/s/ Thomas A. Hays*                                 Director
-------------------
    THOMAS A. HAYS

                                     II - 5
/s/ Richard A. Liddy*                               Director
---------------------
    RICHARD A. LIDDY

                                                    Director
---------------------
    GORDAN R. LOHMAN

/s/ Richard A. Lumpkin*                             Director
-----------------------
    RICHARD A. LUMPKIN

/s/ John Peters MacCarthy*                          Director
--------------------------
    JOHN PETERS MACCARTHY

                                                    Director
------------------------
    HANNE M. MERRIMAN

/s/ Paul L. Miller, Jr.*                            Director
------------------------
    PAUL L. MILLER, JR.

/s/ Robert H. Quenon*                               Director
---------------------
    ROBERT H. QUENON

/s/ Harvey Saligman*                                Director
--------------------
    HARVEY SALIGMAN

/s/ Charles J. Schukai*                             Director
-----------------------
    CHARLES J. SCHUKAI

/s/ Janet McAfee Weakley*                           Director
-------------------------
    JANET MCAFEE WEAKLEY

                                     II - 6
Director
-----------------------
    JAMES W. WOGSLAND

                                                     *By  /s/ James C. Thompson
                                                           ---------------------
                                                              JAMES C. THOMPSON
                                                               Attorney-In-Fact

                                     II - 7
[AMEREN CORPORATION LETTERHEAD]

                                 April 23, 1998                        EXHIBIT 5

Ameren Corporation
1901 Chouteau Avenue
St. Louis, Missouri  63103

       Re:   Registration Statement on Form S-8 Relating to 4,000,000  Shares of
             Common Stock, Including Related Rights

Ladies and Gentlemen:

       I have examined the Registration Statement on Form S-8 (the "Registration
Statement") filed by Ameren Corporation, a Missouri corporation (the "Company"),
with the Securities and Exchange Commission on April 23, 1998 in connection with
the  registration  under the  Securities  Act of 1933, as amended,  of 4,000,000
shares of the Common Stock,  $.01 par value per share,  including related rights
(the  "Common  Stock"),  of the Company to be offered  and sold  pursuant to the
Ameren Corporation Long-Term Incentive Plan of 1998 (the "Plan").

       As Vice President and General Counsel of the Company, I have examined the
Restated  Articles  of  Incorporation  and the By-laws of the  Company,  each as
amended to the date  hereof,  the  records of  corporate  proceedings  and other
actions taken by the Company in connection with the authorization,  issuance and
sale of the Common Stock and such other documents and materials as I have deemed
necessary or appropriate to enable me to deliver this opinion.

       Based upon the foregoing, I am of the opinion that:

       Subject  to (i) compliance  with  applicable  state securities laws, (ii)
approval of  the Plan by the Securities and Exchange Commission under the Public
Utility Holding Company Act  of 1935, and (iii) the filing and  effectiveness of
the  Registration  Statement  with the Securities and Exchange  Commission,  the
Common Stock,  when issued and sold in the manner described in the  Registration
Statement,  will be legally issued, fully paid and nonassessable.

       I hereby  consent  to the  filing of this  opinion  as an  exhibit to the
Registration Statement.

                                            Yours truly,

                                          /s/ William E. Jaudes
                                          ----------------------
                                             William E. Jaudes
                                             Vice President and General Counsel
                                             Ameren Corporation

                                     II - 8
[PRICE WATERHOUSE LLP LETTERHEAD]

                                                                    EXHIBIT 23.1

                       CONSENT OF INDEPENDENT ACCOUNTANTS

       We hereby consent to the  incorporation by reference in this Registration
Statement on Form S-8 of our report  dated  February 5, 1998,  which  appears on
page 17 of the 1997 Annual Report to Shareholders of Ameren  Corporation,  which
is incorporated by reference in Ameren  Corporation's Annual Report on Form 10-K
for the year ended  December 31, 1997. We also consent to the  incorporation  by
reference  in this  Registration  Statement  on  Form  S-8 of our  report  dated
December  17,  1997,  which  appears  on page 9 of  Exhibit  99-2 to the  Ameren
Corporation  Current Report on Form 8-K dated December 31, 1997, with respect to
the supplemental  consolidated  financial statements of Ameren Corporation as of
December  31, 1996 and 1995 and for each of the three years in the period  ended
December 31, 1996, except as such Ameren Corporation financial statements relate
to Central Illinois Public Service Company and CIPSCO  Investment  Company.  The
Central Illinois Public Service Company and CIPSCO Investment  Company financial
statements were audited by another  independent  accountant.  We also consent to
the  incorporation by reference in the  Registration  Statement on Form S-4 (No.
33-64165) of Ameren  Corporation dated November 13, 1995 (the "Form S-4") of our
report  dated  February  1, 1996,  which  appears  on page 16 of Union  Electric
Company's 1995 Annual Report to Shareholders  which is incorporated by reference
in Union  Electric  Company's  Annual  Report  on Form  10-K for the year  ended
December 31, 1995, which Form 10-K is incorporated by reference in the Form S-4.
The Form S-4 is incorporated by reference in this Registration Statement on Form
S-8.  We  also  consent  to the  application  of our  reports  to the  Financial
Statement  Schedules,  which  appear on page 10 of Ameren  Corporation's  Annual
Report on Form 10-K for the year ended  December  31,  1997 and page 12 of Union
Electric  Company's  Annual Report on Form 10-K for the year ended  December 31,
1995,  for each of the five years in the period ended  December  31, 1997,  when
such Schedules are read in conjunction with the financial statements referred to
in our reports dated February 5, 1998 and February 1, 1996.

/S/ Price Waterhouse LLP
-------------------------
    Price Waterhouse LLP
    St. Louis, Missouri
    April 23, 1998

                                     II - 9
[ARTHUR ANDERSEN LLP LETTERHEAD]

                                                                    Exhibit 23.2

                               ARTHUR ANDERSEN LLP

                    CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

         As   independent   public   accountants,   we  hereby  consent  to  the
incorporation by reference in this  Registration  Statement of our reports dated
January 31,  1997,  January 26, 1996,  and January 27, 1995,  included in CIPSCO
Incorporated's  Form 10-K for the years ended December 31, 1996,  1995 and 1994,
respectively,  and to all  references to our Firm included in this  Registration
Statement.

                                                 /S/ Arthur Andersen LLP
                                                 ------------------------
                                                     ARTHUR ANDERSEN LLP

Chicago, Illinois
April 23, 1998

                                     II - 10
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Charles W.
Mueller hereby  appoints  Donald E. Brandt and/or James C. Thompson the true and
lawful  attorneys-in-fact  of the  undersigned,  for and in the name,  place and
stead of the undersigned, to affix the name of the undersigned as a Director and
as Chairman of The Board,  President,  and Chief  Executive  Officer,  of Ameren
Corporation to a  Registration  Statement(s)  and any  amendments  thereto to be
filed with the  Securities and Exchange  Commission  under the Securities Act of
1933,  covering the issue of Common Stock under the  dividend  reinvestment  and
stock purchase plan,  stock  incentive  plan, and savings  investment  plans, as
authorized  by the Company's  Board of Directors on December 17, 1997,  and, for
the  performance of the same acts, each with power to appoint in their place and
stead  and  as  their  substitute,   one  or  more   attorneys-in-fact  for  the
undersigned,  with full power of revocation; hereby ratifying and confirming all
that said attorneys-in-fact may do by virtue hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.

                                              Charles W. Mueller      (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Charles W. Mueller,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                Barbara Lungwitz
                                                ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Donald E.
Brandt hereby appoints  Charles W. Mueller and/or James C. Thompson the true and
lawful  attorneys-in-fact  of the  undersigned,  for and in the name,  place and
stead of the undersigned,  to affix the name of the undersigned as the principal
financial  and  accounting  officer  of  Ameren  Corporation  to a  Registration
Statement(s)  and any  amendments  thereto to be filed with the  Securities  and
Exchange  Commission  under the  Securities  Act of 1933,  covering the issue of
Common Stock under the dividend  reinvestment  and stock  purchase  plan,  stock
incentive  plan, and savings  investment  plans,  as authorized by the Company's
Board of Directors on December 17, 1997,  and, for the  performance  of the same
acts,  each  with  power  to  appoint  in their  place  and  stead  and as their
substitute,  one or more attorneys-in-fact for the undersigned,  with full power
of revocation;  hereby ratifying and confirming all that said  attorneys-in-fact
may do by virtue hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                                  Donald E. Brandt    (L.S.)
                                                  --------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Donald E. Brandt, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                    Barbara Lungwitz
                                                    ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  William E.
Cornelius  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                              William E. Cornelius    (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared William E. Cornelius,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                   Barbara Lungwitz
                                                   ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned  Clifford L.
Greenwalt  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 31st day of December, 1997.
                                            Clifford L. Greenwalt    (L.S.)
                                            -------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally appeared Clifford L. Greenwalt,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                              Barbara Lungwitz
                                              ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Thomas A.
Hays hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James C.
Thompson the true and lawful  attorneys-in-fact  of the undersigned,  for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 20th day of December, 1997.
                                                Thomas A. Hays        (L.S.)
                                                ----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 20th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Thomas A. Hays, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                 Barbara Lungwitz
                                                 ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Richard A.
Liddy hereby appoints Charles W. Mueller and/or Donald E. Brandt and/or James C.
Thompson the true and lawful  attorneys-in-fact  of the undersigned,  for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                               Richard A. Liddy       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Richard A. Liddy, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                 Barbara Lungwitz
                                                 ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Richard A.
Lumpkin hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 31st day of December, 1997.
                                             Richard A. Lumpkin       (L.S.)
                                             -------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Richard A. Lumpkin,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                 Barbara Lungwitz
                                                 ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned  John Peters
MacCarthy  hereby  appoints  Charles W. Mueller  and/or  Donald E. Brandt and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the name,  place and stead of the  undersigned,  to affix the name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                           John Peters MacCarthy      (L.S.)
                                           ---------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally appeared John Peters MacCarthy,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                             Barbara Lungwitz
                                             ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

               KNOW ALL MEN BY THESE PRESENTS:  That  the  undersigned  Paul  L.
Miller,  Jr. hereby  appoints Charles W. Mueller and/or Donald E. Brandt  and/or
James C. Thompson the true and lawful attorneys-in-fact of the undersigned,  for
and in the  name,  place  and  stead  of the  undersigned,  to  affix  the  name
of  the  undersigned as  a  Director of  Ameren  Corporation to  a  Registration
Statement(s)and any  amendments  thereto to be filed  with  the  Securities  and
Exchange  Commission  under the  Securities Act of 1933,  covering  the issue of
Common Stock  under  the dividend  reinvestment  and  stock purchase plan, stock
incentive plan, and savings  investment plans, as authorized  by  the  Company's
Board of Directors on December 17, 1997, and, for  the performance  of the  same
acts, each with  power to  appoint  in  their  place  and  stead  and  as  their
substitute, one or more attorneys-in-fact for the  undersigned,  with full power
of revocation; hereby ratifying and confirming all that  said  attorneys-in-fact
may do by  virtue hereof.
              IN WITNESS WHEREOF, the undersigned has hereunto set his hand  and
seal this 31st day of December, 1997.
                                              Paul L. Miller, Jr.     (L.S.)
                                              ------------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 31st day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Paul L. Miller,  Jr.,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                               Barbara Lungwitz
                                               ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE  PRESENTS:  That the  undersigned  Robert H.
Quenon hereby  appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 24th day of December, 1997.
                                               Robert H. Quenon       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 24th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Robert H. Quenon, known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                               Barbara Lungwitz
                                               ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW  ALL MEN BY  THESE  PRESENTS:  That  the  undersigned  Harvey
Saligman hereby appoints Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                               Harvey Saligman       (L.S.)
                                               ----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State, personally appeared Harvey Saligman,  known
to me to be the person  described  in and who executed  the  foregoing  power of
attorney  and  acknowledged  to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                               Barbara Lungwitz
                                               ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the  undersigned  Charles J.
Schukai hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 23rd day of December, 1997.
                                              Charles J. Schukai     (L.S.)
                                              -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 23rd day of  December,  1997,  before me, the  undersigned
Notary  Public in and for said State,  personally  appeared  Charles J. Schukai,
known to me to be the person  described in and who executed the foregoing  power
of attorney and acknowledged to me that he executed the same as his free act and
deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                               Barbara Lungwitz
                                               ----------------
EXHIBIT 24

                                POWER OF ATTORNEY

              KNOW ALL MEN BY THESE PRESENTS:  That the undersigned Janet McAfee
Weakley hereby appoints  Charles W. Mueller and/or Donald E. Brandt and/or James
C. Thompson the true and lawful attorneys-in-fact of the undersigned, for and in
the  name,  place  and  stead  of the  undersigned,  to  affix  the  name of the
undersigned as a Director of Ameren  Corporation to a Registration  Statement(s)
and any  amendments  thereto  to be  filed  with  the  Securities  and  Exchange
Commission under the Securities Act of 1933,  covering the issue of Common Stock
under the dividend  reinvestment  and stock purchase plan, stock incentive plan,
and savings  investment plans, as authorized by the Company's Board of Directors
on December 17, 1997, and, for the performance of the same acts, each with power
to  appoint  in their  place  and  stead  and as their  substitute,  one or more
attorneys-in-fact  for the  undersigned,  with full power of revocation;  hereby
ratifying  and  confirming  all that  said  attorneys-in-fact  may do by  virtue
hereof.
              IN WITNESS WHEREOF,  the undersigned has hereunto set his hand and
seal this 19th day of December, 1997.
                                               Janet M. Weakley       (L.S.)
                                               -----------------------------

STATE OF MISSOURI             )
                              )  SS.
CITY OF ST. LOUIS             )

              On this 19th day of  December,  1997,  before me, the  undersigned
Notary Public in and for said State,  personally  appeared Janet McAfee Weakley,
known to me to be the person  described in and who executed the foregoing  power
of attorney  and  acknowledged  to me that she executed the same as her free act
and deed for the purposes therein stated.

              IN TESTIMONY  WHEREOF,  I have hereunto set my hand and affixed my
official seal.

                                                Kathleen D. O'Reilly
                                                --------------------