<PAGE>   1
As filed with the Securities and Exchange Commission on December 22, 2000
                                                   Registration No. 333--
                                                                         -------
                     U.S. SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

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

                           MERCANTILE BANK CORPORATION

              (Exact number of issuer as specified in its charter)

          Michigan                                    38-3360865
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
of incorporation or organization)

             216 North Division Avenue, Grand Rapids, Michigan 49503
               (Address of Principal Executive Offices) (Zip Code)

                           MERCANTILE BANK CORPORATION
                         2000 EMPLOYEE STOCK OPTION PLAN
                            (Full title of the plan)

                        GERALD R. JOHNSON, JR., CHAIRMAN
                           Mercantile Bank Corporation
                            216 North Division Avenue
                          Grand Rapids, Michigan 49503
                     (Name and Address of Agent for service)
                                 (616) 242-9000
          (Telephone number, including area code, of agent for service)

                          COPIES OF COMMUNICATIONS TO:
                               JEROME M. SCHWARTZ
                              Dickinson Wright PLLC
                         500 Woodward Avenue, Suite 4000
                             Detroit, Michigan 48226

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>

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

                                                             Proposed Maximum           Proposed
      Title of Securities            Amount to be           Offering Price Per       Maximum Aggregate        Amount of
       to be Registered*              Registered*               Share**              Offering Price**      Registration Fee

-------------------------------- ---------------------- ------------------------- ------------------------ -----------------
<S>                              <C>                       <C>                     <C>                    <C>
         Common Stock               120,000 Shares              $12.75                  $1,530,000            $383

-------------------------------- ---------------------- ------------------------- ------------------------ -----------------
</TABLE>

*  Includes an indeterminate number of additional shares that may be issued to
adjust for any subdivision of shares or other capital adjustment, stock split,
stock dividend, or other increase in shares effected without receipt of
consideration by the issuer.

** Estimated pursuant to Rule 457(c) solely for purposes of calculating the
registration fee, based upon the average of the high bid and low ask prices on
December 19, 2000, as reported on the Nasdaq National Market.


<PAGE>   2


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

         Mercantile Bank Corporation ("Mercantile") incorporates by reference in
this Registration Statement the following documents previously filed with the
Securities and Exchange Commission (the "Commission") under the Securities
Exchange Act of 1934, as amended (the "Exchange Act"):

         1. Mercantile's Annual Report on Form 10-KSB for the year ended
December 31, 1999.

         2. Mercantile's Quarterly Reports on Form 10-Q for the quarters ended
March 31, 2000, June 30, 2000 and September 30, 2000.

         3. The description of Mercantile's common stock in Item 1 of
Mercantile's Form 8-A registration statement dated July 9, 1999, filed with the
Commission under the Exchange Act on July 15, 1999, including any amendment or
report filed for the purpose of updating such description.

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

ITEM 4.  DESCRIPTION OF SECURITIES

Not Applicable.

ITEM 5.  INTEREST OF NAMED EXPERTS AND COUNSEL

         As of December 1, 2000, members of Dickinson Wright PLLC who perform
services for Mercantile owned approximately 8,300 shares of common stock of
Mercantile.



                                       1
<PAGE>   3


ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Indemnification

         Mercantile's Articles of Incorporation provide that Mercantile shall
indemnify its present and past directors, officers, and such other persons as
the Board of Directors may authorize to the full extent permitted by law.

         Mercantile's Bylaws contain indemnification provisions concerning third
party actions as well as actions in the right of Mercantile. The Bylaws provide
that Mercantile shall indemnify any person who was or is a party or is
threatened to be made a party to 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 Mercantile) by reason of the fact
that he or she is or was a director or officer of Mercantile or while serving as
such a director or officer, is or was serving at the request of Mercantile as a
director, officer, partner, trustee, employee or agent of another foreign or
domestic corporation, partnership, joint venture, trust or other enterprise,
whether for profit or not, against expenses (including attorney's fees),
judgments, penalties, fees and amounts paid in settlement actually and
reasonably incurred by him or her in connection with such action, suit or
proceeding if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of Mercantile or its
shareholders and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his or her conduct was unlawful.

         Federal Deposit Insurance Corporation regulations impose limitations on
indemnification payments which could restrict, in certain circumstances,
payments by Mercantile or the Bank to their respective directors or officers
otherwise permitted under the Michigan Business Corporation Act ("MBCA") or the
Michigan Banking Code, respectively.

         With respect to derivative actions, the Bylaws provide that Mercantile
shall indemnify any person who was or is a party to or is threatened to be made
a party to any threatened, pending or completed action or suit by or in the
right of Mercantile to procure a judgment in its favor by reason of the fact
that he or she is or was a director or officer of Mercantile, or while serving
as such a director or officer, is or was serving at the request of Mercantile as
a director, officer, partner, trustee, employee or agent of another foreign or
domestic corporation, partnership, joint venture, trust or other enterprise,
whether for profit or not, against expenses (including attorney's fees) and
amounts paid in settlement actually and reasonably incurred by him or her in
connection with the action or suit if he or she acted in good faith and in a
manner he or she reasonably believed to be in or not opposed to the best
interests of Mercantile or its shareholders. No indemnification is provided in
the Bylaws in respect of any claim, issue or matter in which such person has
been found liable to Mercantile except to the extent that a court of competent
jurisdiction determines upon application that, despite


                                       2
<PAGE>   4

the adjudication of liability but in view of all circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses which
such court shall deem proper.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
Mercantile pursuant to the provisions discussed above or otherwise, Mercantile
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable.

         Mercantile has purchased directors' and officers' liability insurance
for directors and officers of Mercantile.

         Limitation of Director Liability

         The MBCA permits corporations to limit the personal liability of their
directors in certain circumstances. Mercantile's Articles of Incorporation
provide that the director of Mercantile shall not be personally liable to
Mercantile or its shareholders for monetary damages for breach of the director's
fiduciary duty. However, they do not eliminate or limit the liability of a
director for any breach of a duty, act or omission for which the elimination or
limitation of liability is not permitted by the MBCA, currently including,
without limitation, the following: (1) breach of the director's duty of loyalty
to Mercantile or its shareholders; (2) acts or omissions not in good faith or
that involve intentional misconduct or a knowing violation of the law; (3)
illegal loans, distributions of dividends or assets, or stock purchases as
described in Section 551(1) of the MBCA; and (4) transactions from which the
director derived an improper personal benefit.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

Not Applicable





                                       3
<PAGE>   5


ITEM 8.  EXHIBITS

The following exhibits are filed with this Registration Statement:

       Exhibit
       Number                      Exhibit
       ------                      -------

         4            Article III of the Articles of Incorporation of Mercantile
                      is incorporated by reference to Exhibit 3.1 of
                      Mercantile's Registration Statement on Form SB-2
                      (Commission File No. 333-33081) that became effective on
                      October 23, 1997

         5            Opinion of Counsel, Dickinson Wright PLLC

       23(a)          Consent of Crowe, Chizek and Company LLP

       23(b)          Consent of Dickinson Wright PLLC is included in
                      Exhibit 5

ITEM 9.  UNDERTAKINGS

         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, provided that 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 (1)(i) and (1)(ii) do not apply if 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 the Registration Statement.


                                       4
<PAGE>   6

         (2) That, for purposes of determining any liability under the
Securities Act of 1933, each such post-effective amendment 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.

         (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.

         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.

         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 foregoing provisions, 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 of whether or not such indemnification by it is
against public policy as expressed in the Act and will be governed by the final
adjudication of such issue.




                                       5
<PAGE>   7


                                   SIGNATURES

         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 Grand Rapids and State of Michigan on December 21, 2000

                               MERCANTILE BANK CORPORATION


                               By /s/ Gerald R. Johnson, Jr.
                                  ----------------------------------------------
                                  Gerald R. Johnson, Jr., Chairman of the
                                  Board and Chief Executive Officer

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on December 21, 2000.

/s/ Betty S. Burton                       /s/ Lawrence W. Larsen
---------------------------------------   --------------------------------------
Betty S. Burton, Director                 Lawrence W. Larsen, Director

/s/ Edward J. Clark                       /s/ Calvin D. Murdock
---------------------------------------   --------------------------------------
Edward J. Clark, Director                 Calvin D. Murdock, Director

/s/ Peter A. Cordes                       /s/ Michael H. Price
---------------------------------------   --------------------------------------
Peter A. Cordes, Director                 Michael H. Price, President and Chief
                                          Operating Officer

/s/ C. John Gill                          /s/ Dale J. Visser
---------------------------------------   --------------------------------------
C. John Gill, Director                    Dale J. Visser, Director

/s/ David M. Hecht                        /s/ Donald Williams, Sr.
---------------------------------------   --------------------------------------
David M. Hecht, Director                  Donald Williams, Sr., Director

/s/ Gerald R. Johnson, Jr.                /s/ Robert M. Wynalda
---------------------------------------   --------------------------------------
Gerald R. Johnson, Jr., Chairman of the   Robert M. Wynalda, Director
Board and Chief Executive Officer
(principal executive officer)

/s/ Susan K. Jones                        /s/ Charles E. Christmas
---------------------------------------   --------------------------------------
Susan K. Jones, Director                  Charles E. Christmas, Senior Vice
                                          President, Chief Financial Officer and
                                          Treasurer (principal financial and
                                          accounting officer)










                                       6
<PAGE>   8


                                  EXHIBIT INDEX


Exhibit
Number                          Exhibit
------                          -------

4                     Article III of the Articles of Incorporation of Mercantile
                      is incorporated by reference to Exhibit 3.1 of
                      Mercantile's Registration Statement on Form SB-2
                      (Commission File No. 333-33081) that became effective on
                      October 23, 1997

5                     Opinion of Counsel, Dickinson Wright PLLC

23(a)                 Consent of Crowe, Chizek and Company LLP

23(b)                 Consent of Dickinson Wright PLLC is included in
                      Exhibit 5
[{"type": "S-8", "sequence": "1", "filename": "k59145s-8.txt", "description": "REGISTRATION STATEMENT ON FORM S-8", "secsgml_size_bytes": 18867}]
{"company-data": {"conformed-name": "MERCANTILE BANK CORP", "cik": "0001042729", "assigned-sic": "6022", "irs-number": "383360865", "state-of-incorporation": "MI", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-52620", "film-number": "794929"}, "business-address": {"street1": "42 DEER RUN DRIVE", "city": "ADA", "state": "MI", "zip": "49301", "phone": "6166760201"}, "mail-address": {"street1": "42 DEER RUN DRIVE", "city": "ADA", "state": "MI", "zip": "49301"}}
1
As filed with the Securities and Exchange Commission on December 22, 2000
                                                   Registration No. 333--
                                                                         -------
                     U.S. SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

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

                           MERCANTILE BANK CORPORATION

              (Exact number of issuer as specified in its charter)

          Michigan                                    38-3360865
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
of incorporation or organization)

             216 North Division Avenue, Grand Rapids, Michigan 49503
               (Address of Principal Executive Offices) (Zip Code)

                           MERCANTILE BANK CORPORATION
                         2000 EMPLOYEE STOCK OPTION PLAN
                            (Full title of the plan)

                        GERALD R. JOHNSON, JR., CHAIRMAN
                           Mercantile Bank Corporation
                            216 North Division Avenue
                          Grand Rapids, Michigan 49503
                     (Name and Address of Agent for service)
                                 (616) 242-9000
          (Telephone number, including area code, of agent for service)

                          COPIES OF COMMUNICATIONS TO:
                               JEROME M. SCHWARTZ
                              Dickinson Wright PLLC
                         500 Woodward Avenue, Suite 4000
                             Detroit, Michigan 48226

                         CALCULATION OF REGISTRATION FEE
-------------------------------- ---------------------- ------------------------- ------------------------ -----------------

                                                             Proposed Maximum           Proposed
      Title of Securities            Amount to be           Offering Price Per       Maximum Aggregate        Amount of
       to be Registered*              Registered*               Share**              Offering Price**      Registration Fee

-------------------------------- ---------------------- ------------------------- ------------------------ -----------------
Common Stock               120,000 Shares              $12.75                  $1,530,000            $383

-------------------------------- ---------------------- ------------------------- ------------------------ -----------------
*  Includes an indeterminate number of additional shares that may be issued to
adjust for any subdivision of shares or other capital adjustment, stock split,
stock dividend, or other increase in shares effected without receipt of
consideration by the issuer.

** Estimated pursuant to Rule 457(c) solely for purposes of calculating the
registration fee, based upon the average of the high bid and low ask prices on
December 19, 2000, as reported on the Nasdaq National Market.
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

         Mercantile Bank Corporation ("Mercantile") incorporates by reference in
this Registration Statement the following documents previously filed with the
Securities and Exchange Commission (the "Commission") under the Securities
Exchange Act of 1934, as amended (the "Exchange Act"):

         1. Mercantile's Annual Report on Form 10-KSB for the year ended
December 31, 1999.

         2. Mercantile's Quarterly Reports on Form 10-Q for the quarters ended
March 31, 2000, June 30, 2000 and September 30, 2000.

         3. The description of Mercantile's common stock in Item 1 of
Mercantile's Form 8-A registration statement dated July 9, 1999, filed with the
Commission under the Exchange Act on July 15, 1999, including any amendment or
report filed for the purpose of updating such description.

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

ITEM 4.  DESCRIPTION OF SECURITIES

Not Applicable.

ITEM 5.  INTEREST OF NAMED EXPERTS AND COUNSEL

         As of December 1, 2000, members of Dickinson Wright PLLC who perform
services for Mercantile owned approximately 8,300 shares of common stock of
Mercantile.

                                       1
3

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Indemnification

         Mercantile's Articles of Incorporation provide that Mercantile shall
indemnify its present and past directors, officers, and such other persons as
the Board of Directors may authorize to the full extent permitted by law.

         Mercantile's Bylaws contain indemnification provisions concerning third
party actions as well as actions in the right of Mercantile. The Bylaws provide
that Mercantile shall indemnify any person who was or is a party or is
threatened to be made a party to 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 Mercantile) by reason of the fact
that he or she is or was a director or officer of Mercantile or while serving as
such a director or officer, is or was serving at the request of Mercantile as a
director, officer, partner, trustee, employee or agent of another foreign or
domestic corporation, partnership, joint venture, trust or other enterprise,
whether for profit or not, against expenses (including attorney's fees),
judgments, penalties, fees and amounts paid in settlement actually and
reasonably incurred by him or her in connection with such action, suit or
proceeding if he or she acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of Mercantile or its
shareholders and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his or her conduct was unlawful.

         Federal Deposit Insurance Corporation regulations impose limitations on
indemnification payments which could restrict, in certain circumstances,
payments by Mercantile or the Bank to their respective directors or officers
otherwise permitted under the Michigan Business Corporation Act ("MBCA") or the
Michigan Banking Code, respectively.

         With respect to derivative actions, the Bylaws provide that Mercantile
shall indemnify any person who was or is a party to or is threatened to be made
a party to any threatened, pending or completed action or suit by or in the
right of Mercantile to procure a judgment in its favor by reason of the fact
that he or she is or was a director or officer of Mercantile, or while serving
as such a director or officer, is or was serving at the request of Mercantile as
a director, officer, partner, trustee, employee or agent of another foreign or
domestic corporation, partnership, joint venture, trust or other enterprise,
whether for profit or not, against expenses (including attorney's fees) and
amounts paid in settlement actually and reasonably incurred by him or her in
connection with the action or suit if he or she acted in good faith and in a
manner he or she reasonably believed to be in or not opposed to the best
interests of Mercantile or its shareholders. No indemnification is provided in
the Bylaws in respect of any claim, issue or matter in which such person has
been found liable to Mercantile except to the extent that a court of competent
jurisdiction determines upon application that, despite

                                       2
4

the adjudication of liability but in view of all circumstances of the case, such
person is fairly and reasonably entitled to indemnity for such expenses which
such court shall deem proper.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
Mercantile pursuant to the provisions discussed above or otherwise, Mercantile
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable.

         Mercantile has purchased directors' and officers' liability insurance
for directors and officers of Mercantile.

         Limitation of Director Liability

         The MBCA permits corporations to limit the personal liability of their
directors in certain circumstances. Mercantile's Articles of Incorporation
provide that the director of Mercantile shall not be personally liable to
Mercantile or its shareholders for monetary damages for breach of the director's
fiduciary duty. However, they do not eliminate or limit the liability of a
director for any breach of a duty, act or omission for which the elimination or
limitation of liability is not permitted by the MBCA, currently including,
without limitation, the following: (1) breach of the director's duty of loyalty
to Mercantile or its shareholders; (2) acts or omissions not in good faith or
that involve intentional misconduct or a knowing violation of the law; (3)
illegal loans, distributions of dividends or assets, or stock purchases as
described in Section 551(1) of the MBCA; and (4) transactions from which the
director derived an improper personal benefit.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

Not Applicable

                                       3
5

ITEM 8.  EXHIBITS

The following exhibits are filed with this Registration Statement:

       Exhibit
       Number                      Exhibit
       ------                      -------

         4            Article III of the Articles of Incorporation of Mercantile
                      is incorporated by reference to Exhibit 3.1 of
                      Mercantile's Registration Statement on Form SB-2
                      (Commission File No. 333-33081) that became effective on
                      October 23, 1997

         5            Opinion of Counsel, Dickinson Wright PLLC

       23(a)          Consent of Crowe, Chizek and Company LLP

       23(b)          Consent of Dickinson Wright PLLC is included in
                      Exhibit 5

ITEM 9.  UNDERTAKINGS

         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, provided that 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 (1)(i) and (1)(ii) do not apply if 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 the Registration Statement.

                                       4
6

         (2) That, for purposes of determining any liability under the
Securities Act of 1933, each such post-effective amendment 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.

         (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.

         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.

         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 foregoing provisions, 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 of whether or not such indemnification by it is
against public policy as expressed in the Act and will be governed by the final
adjudication of such issue.

                                       5
7

                                   SIGNATURES

         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 Grand Rapids and State of Michigan on December 21, 2000

                               MERCANTILE BANK CORPORATION

                               By /s/ Gerald R. Johnson, Jr.
                                  ----------------------------------------------
                                  Gerald R. Johnson, Jr., Chairman of the
                                  Board and Chief Executive Officer

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on December 21, 2000.

/s/ Betty S. Burton                       /s/ Lawrence W. Larsen
---------------------------------------   --------------------------------------
Betty S. Burton, Director                 Lawrence W. Larsen, Director

/s/ Edward J. Clark                       /s/ Calvin D. Murdock
---------------------------------------   --------------------------------------
Edward J. Clark, Director                 Calvin D. Murdock, Director

/s/ Peter A. Cordes                       /s/ Michael H. Price
---------------------------------------   --------------------------------------
Peter A. Cordes, Director                 Michael H. Price, President and Chief
                                          Operating Officer

/s/ C. John Gill                          /s/ Dale J. Visser
---------------------------------------   --------------------------------------
C. John Gill, Director                    Dale J. Visser, Director

/s/ David M. Hecht                        /s/ Donald Williams, Sr.
---------------------------------------   --------------------------------------
David M. Hecht, Director                  Donald Williams, Sr., Director

/s/ Gerald R. Johnson, Jr.                /s/ Robert M. Wynalda
---------------------------------------   --------------------------------------
Gerald R. Johnson, Jr., Chairman of the   Robert M. Wynalda, Director
Board and Chief Executive Officer
(principal executive officer)

/s/ Susan K. Jones                        /s/ Charles E. Christmas
---------------------------------------   --------------------------------------
Susan K. Jones, Director                  Charles E. Christmas, Senior Vice
                                          President, Chief Financial Officer and
                                          Treasurer (principal financial and
                                          accounting officer)

                                       6
8

                                  EXHIBIT INDEX

Exhibit
Number                          Exhibit
------                          -------

4                     Article III of the Articles of Incorporation of Mercantile
                      is incorporated by reference to Exhibit 3.1 of
                      Mercantile's Registration Statement on Form SB-2
                      (Commission File No. 333-33081) that became effective on
                      October 23, 1997

5                     Opinion of Counsel, Dickinson Wright PLLC

23(a)                 Consent of Crowe, Chizek and Company LLP

23(b)                 Consent of Dickinson Wright PLLC is included in
                      Exhibit 5