As filed with the Securities and Exchange Commission on March 20, 1998
                                            Registration No. 333-_________
--------------------------------------------------------------------------
--------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                             PS BUSINESS PARKS, INC.
                  (FORMERLY PUBLIC STORAGE PROPERTIES XI, INC.)
             (Exact name of registrant as specified in its charter)

                                   California
         (State or other jurisdiction of incorporation or organization)

                                   95-4300881
                      (I.R.S. Employer Identification No.)

                            701 Western Avenue
                         Glendale, California 91201-2397
             (Address of Principal Executive Offices with Zip Code)

                             PS BUSINESS PARKS, INC.
                      1997 STOCK OPTION AND INCENTIVE PLAN
                            (Full Title of the Plan)

                                 HARVEY LENKIN
                             PS Business Parks, Inc.
                               701 Western Avenue
                         Glendale, California 91201-2397
                                 (818) 244-8080
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
                                 --------------

                                 With a copy to:

                              DAVID GOLDBERG, ESQ.
                             PS Business Parks, Inc.
                               701 Western Avenue
                         Glendale, California 91201-2397
                                 --------------

                         CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------
--------------------------------------------------------------------------
<TABLE>
<CAPTION>

                                             Proposed         Proposed
                             Amount           maximum          maximum        Amount of
Title of securities           to be        offering price      aggregate     registration
 to be registered          registered         per share     offering price       fee
-----------------------------------------------------------------------------------------
<S>                      <C>               <C>              <C>              <C>
Common Stock, $.01 par
 value per share         1,500,000 Shares    $23.0625<F1>    $34,593,750<F1>    $10,206

</TABLE>

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


   <F1> Estimated  solely  for the  purpose of  calculating  the filing fee and,
        pursuant to Rule 457(c), based on the average of the high and low prices
        of the Common Stock on the American Stock Exchange on March 17, 1998.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The documents  containing  the  information  specified in Part I will be
sent or given to employees as specified by Rule  428(b)(1).  In accordance  with
the  instructions  to Part I of Form S-8, such  documents will not be filed with
the Securities and Exchange Commission (the "Commission") either as part of this
Registration  Statement or as prospectuses or prospectus supplements pursuant to
Rule 424.

                                     PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

        The following documents filed by PS Business Parks, Inc., formerly known
as Public Storage  Properties XI, Inc. (the "Company"),  with the Securities and
Exchange   Commission  are  incorporated  in  this  Registration   Statement  by
reference:  (i) the Annual  Report on Form 10-K for the year ended  December 31,
1997,  (ii) the  Current  Report on Form 8-K/A  dated  December  17, 1997 (filed
January 8, 1998),  as amended by a Form 8-K/A  dated  January 29, 1998 and (iii)
the description of the Company's  Common Stock (formerly Common Stock Series A),
$.01 par value per share,  contained in the Company's  Registration Statement on
Form 8-A,  effective  March 15, 1991, as  supplemented by the description of the
Company's  Common Stock  contained in the Proxy  Statement and Prospectus  dated
February 5, 1998  included in the Company's  Registration  Statement on Form S-4
(No. 333-45405).

        All documents filed by the Company pursuant to Sections 13(a), 13(c), 14
and 15(d) of the  Securities  Exchange  Act of 1934 on or after the date of this
Registration Statement and prior to the filing of a post-effective  amendment to
this Registration  Statement which indicates that all securities  offered hereby
have been sold or which  deregisters all securities then remaining  unsold,  are
deemed to be incorporated by reference in this Registration  Statement and shall
be a part thereof from the date of filing of those documents.

ITEM 4.  DESCRIPTION OF SECURITIES

        A description of the Company's  Common Stock,  $.01 par value per share,
is incorporated by reference under Item 3.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

                               LEGAL OPINIONS

        David Goldberg, Vice President and Counsel of the Company, has delivered
an  opinion  to the  effect  that the  shares of Common  Stock  covered  by this
Registration  Statement will be legally issued,  fully paid and  non-assessable.
Mr.  Goldberg  owns 4,056  shares of Common  Stock and has options to acquire an
additional 7,991 shares of Common Stock.

                                   EXPERTS

        The  financial  statements  and related  schedule of the Company for the
year ended  December 31, 1997  appearing in the Company's  Annual Report on Form
10-K have been audited by Ernst & Young LLP, independent  auditors, as set forth
in their  report  included  in the  Company's  Annual  Report  on Form  10-K and
incorporated  herein by reference.  Such financial  statements are  incorporated
herein by reference in reliance  upon such reports  given upon the  authority of
such firm as experts in accounting and auditing.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

        The  Company's  Articles of  Incorporation  provide that the Company may
indemnify  the  agents of the  Company to the  maximum  extent  permitted  under
California law. The Company has also entered into indemnity  agreements with its
management and non-management  directors and executive officers.  The agreements
permit the Company to indemnify  directors and executive officers to the maximum
extent  permitted under California law and prohibit the Company from terminating
its  indemnification  obligations  as to acts or  omissions  of any  director or
executive  officer  occurring before the termination.  The  indemnification  and
limitations  on liability  permitted by the  Articles of  Incorporation  and the
agreements  are subject to the  limitations  set forth by  California  law.  The
Company believes the indemnification agreements will assist it in attracting and
retaining qualified  individuals to serve as directors and executive officers of
the Company.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

        Not applicable.

ITEM 8.  EXHIBITS

        See Exhibit Index contained herein.

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
                 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.

           (2)   That,  for the purpose of determining  any liability  under the
                 Securities  Act of 1933 (the "Act"),  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  that remain
                 unsold at the termination of the offering.

        B. The undersigned  Registrant  hereby  undertakes that, for purposes of
determining any liability under the Act, each filing of the Registrant's  annual
report pursuant to Section 13(a) or 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 Act 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 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.

<PAGE>

                               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 of Glendale,  State of  California,  on the 20th day of
March, 1998.

                                        PS BUSINESS PARKS, INC.

                                        By:  /s/ RONALD L. HAVNER, JR.
                                             --------------------------------
                                             Ronald L. Havner, Jr., President

        Each person whose signature  appears below hereby  authorizes  Ronald L.
Havner, Jr. and Harvey Lenkin, and each of them, as attorney-in-fact, to sign on
his behalf,  individually  and in each  capacity  stated below,  any  amendment,
including post-effective  amendments to this Registration Statement, and to file
the same, with all exhibits thereto, and all documents in connection  therewith,
with the Securities and Exchange Commission.

        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 dates indicated.

     Signature                 Capacity                       Date
     ---------                 --------                       ----

 /s/ RONALD L. HAVNER, JR.     Chairman of the Board,         March 20, 1998
 ------------------------      Chief Executive Officer,
 Ronald L. Havner, Jr.         President, Chief Financial
                               Officer and Director
                               (principal executive officer,
                               principal financial officer
                               and principal accounting
                               officer)

 /s/ HARVEY LENKIN             Director                       March 20, 1998
 ------------------------
 Harvey Lenkin


 /s/ VERN O. CURTIS            Director                       March 20, 1998
 ------------------------
 Vern O. Curtis


 /s/ ARTHUR M. FRIEDMAN        Director                       March 20, 1998
 ------------------------
 Arthur M. Friedman


 /s/ JAMES H. KROPP            Director                       March 20, 1998
 ------------------------
 James H. Kropp


 /s/ ALAN K. PRIBBLE           Director                       March 20, 1998
 ------------------------
 Alan K. Pribble


 /s/ JACK D. STEELE            Director                       March 20, 1998
 ------------------------
 Jack D. Steele

<PAGE>


                                EXHIBIT INDEX

    Exhibit No.           Description

    5.1                   Opinion of David Goldberg as to the legality of the
                          securities being registered.

    23.1                  Consent of independent auditors.

    23.2                  Consent of David Goldberg (included in Exhibit 5.1).

    99.1                  The Company's 1997 Stock Option and Incentive Plan.
[{"type": "S-8", "sequence": "1", "description": "S-8 REGISTRATION STATEMENT", "secsgml_size_bytes": 13947}]
{"company-data": {"conformed-name": "PS BUSINESS PARKS INC/CA", "cik": "0000866368", "assigned-sic": "6798", "irs-number": "954300881", "state-of-incorporation": "CA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-48313", "film-number": "98569726"}, "business-address": {"street1": "701 WESTERN AVE", "street2": "SUITE 200", "city": "GLENDALE", "state": "CA", "zip": "91201-2397", "phone": "8182448080"}, "mail-address": {"street1": "701 WESTERN AVE", "street2": "SUITE 200", "city": "GLENDALE", "state": "CA", "zip": "91201"}, "former-company": {"former-conformed-name": "PUBLIC STORAGE PROPERTIES XI INC", "date-changed": "19930328"}}
As filed with the Securities and Exchange Commission on March 20, 1998
                                            Registration No. 333-_________
--------------------------------------------------------------------------
--------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                             PS BUSINESS PARKS, INC.
                  (FORMERLY PUBLIC STORAGE PROPERTIES XI, INC.)
             (Exact name of registrant as specified in its charter)

                                   California
         (State or other jurisdiction of incorporation or organization)

                                   95-4300881
                      (I.R.S. Employer Identification No.)

                            701 Western Avenue
                         Glendale, California 91201-2397
             (Address of Principal Executive Offices with Zip Code)

                             PS BUSINESS PARKS, INC.
                      1997 STOCK OPTION AND INCENTIVE PLAN
                            (Full Title of the Plan)

                                 HARVEY LENKIN
                             PS Business Parks, Inc.
                               701 Western Avenue
                         Glendale, California 91201-2397
                                 (818) 244-8080
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
                                 --------------

                                 With a copy to:

                              DAVID GOLDBERG, ESQ.
                             PS Business Parks, Inc.
                               701 Western Avenue
                         Glendale, California 91201-2397
                                 --------------

                         CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------
--------------------------------------------------------------------------
Proposed         Proposed
                             Amount           maximum          maximum        Amount of
Title of securities           to be        offering price      aggregate     registration
 to be registered          registered         per share     offering price       fee
-----------------------------------------------------------------------------------------
Common Stock, $.01 par
 value per share         1,500,000 Shares    $23.0625
$34,593,750
$10,206
--------------------------------------------------------------------------
--------------------------------------------------------------------------
Estimated  solely  for the  purpose of  calculating  the filing fee and,
        pursuant to Rule 457(c), based on the average of the high and low prices
        of the Common Stock on the American Stock Exchange on March 17, 1998.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The documents  containing  the  information  specified in Part I will be
sent or given to employees as specified by Rule  428(b)(1).  In accordance  with
the  instructions  to Part I of Form S-8, such  documents will not be filed with
the Securities and Exchange Commission (the "Commission") either as part of this
Registration  Statement or as prospectuses or prospectus supplements pursuant to
Rule 424.

                                     PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

        The following documents filed by PS Business Parks, Inc., formerly known
as Public Storage  Properties XI, Inc. (the "Company"),  with the Securities and
Exchange   Commission  are  incorporated  in  this  Registration   Statement  by
reference:  (i) the Annual  Report on Form 10-K for the year ended  December 31,
1997,  (ii) the  Current  Report on Form 8-K/A  dated  December  17, 1997 (filed
January 8, 1998),  as amended by a Form 8-K/A  dated  January 29, 1998 and (iii)
the description of the Company's  Common Stock (formerly Common Stock Series A),
$.01 par value per share,  contained in the Company's  Registration Statement on
Form 8-A,  effective  March 15, 1991, as  supplemented by the description of the
Company's  Common Stock  contained in the Proxy  Statement and Prospectus  dated
February 5, 1998  included in the Company's  Registration  Statement on Form S-4
(No. 333-45405).

        All documents filed by the Company pursuant to Sections 13(a), 13(c), 14
and 15(d) of the  Securities  Exchange  Act of 1934 on or after the date of this
Registration Statement and prior to the filing of a post-effective  amendment to
this Registration  Statement which indicates that all securities  offered hereby
have been sold or which  deregisters all securities then remaining  unsold,  are
deemed to be incorporated by reference in this Registration  Statement and shall
be a part thereof from the date of filing of those documents.

ITEM 4.  DESCRIPTION OF SECURITIES

        A description of the Company's  Common Stock,  $.01 par value per share,
is incorporated by reference under Item 3.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

                               LEGAL OPINIONS

        David Goldberg, Vice President and Counsel of the Company, has delivered
an  opinion  to the  effect  that the  shares of Common  Stock  covered  by this
Registration  Statement will be legally issued,  fully paid and  non-assessable.
Mr.  Goldberg  owns 4,056  shares of Common  Stock and has options to acquire an
additional 7,991 shares of Common Stock.

                                   EXPERTS

        The  financial  statements  and related  schedule of the Company for the
year ended  December 31, 1997  appearing in the Company's  Annual Report on Form
10-K have been audited by Ernst & Young LLP, independent  auditors, as set forth
in their  report  included  in the  Company's  Annual  Report  on Form  10-K and
incorporated  herein by reference.  Such financial  statements are  incorporated
herein by reference in reliance  upon such reports  given upon the  authority of
such firm as experts in accounting and auditing.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

        The  Company's  Articles of  Incorporation  provide that the Company may
indemnify  the  agents of the  Company to the  maximum  extent  permitted  under
California law. The Company has also entered into indemnity  agreements with its
management and non-management  directors and executive officers.  The agreements
permit the Company to indemnify  directors and executive officers to the maximum
extent  permitted under California law and prohibit the Company from terminating
its  indemnification  obligations  as to acts or  omissions  of any  director or
executive  officer  occurring before the termination.  The  indemnification  and
limitations  on liability  permitted by the  Articles of  Incorporation  and the
agreements  are subject to the  limitations  set forth by  California  law.  The
Company believes the indemnification agreements will assist it in attracting and
retaining qualified  individuals to serve as directors and executive officers of
the Company.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

        Not applicable.

ITEM 8.  EXHIBITS

        See Exhibit Index contained herein.

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
                 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.

           (2)   That,  for the purpose of determining  any liability  under the
                 Securities  Act of 1933 (the "Act"),  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  that remain
                 unsold at the termination of the offering.

        B. The undersigned  Registrant  hereby  undertakes that, for purposes of
determining any liability under the Act, each filing of the Registrant's  annual
report pursuant to Section 13(a) or 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 Act 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 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.
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 of Glendale,  State of  California,  on the 20th day of
March, 1998.

                                        PS BUSINESS PARKS, INC.

                                        By:  /s/ RONALD L. HAVNER, JR.
                                             --------------------------------
                                             Ronald L. Havner, Jr., President

        Each person whose signature  appears below hereby  authorizes  Ronald L.
Havner, Jr. and Harvey Lenkin, and each of them, as attorney-in-fact, to sign on
his behalf,  individually  and in each  capacity  stated below,  any  amendment,
including post-effective  amendments to this Registration Statement, and to file
the same, with all exhibits thereto, and all documents in connection  therewith,
with the Securities and Exchange Commission.

        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 dates indicated.

     Signature                 Capacity                       Date
     ---------                 --------                       ----

 /s/ RONALD L. HAVNER, JR.     Chairman of the Board,         March 20, 1998
 ------------------------      Chief Executive Officer,
 Ronald L. Havner, Jr.         President, Chief Financial
                               Officer and Director
                               (principal executive officer,
                               principal financial officer
                               and principal accounting
                               officer)

 /s/ HARVEY LENKIN             Director                       March 20, 1998
 ------------------------
 Harvey Lenkin

 /s/ VERN O. CURTIS            Director                       March 20, 1998
 ------------------------
 Vern O. Curtis

 /s/ ARTHUR M. FRIEDMAN        Director                       March 20, 1998
 ------------------------
 Arthur M. Friedman

 /s/ JAMES H. KROPP            Director                       March 20, 1998
 ------------------------
 James H. Kropp

 /s/ ALAN K. PRIBBLE           Director                       March 20, 1998
 ------------------------
 Alan K. Pribble

 /s/ JACK D. STEELE            Director                       March 20, 1998
 ------------------------
 Jack D. Steele
EXHIBIT INDEX

    Exhibit No.           Description

    5.1                   Opinion of David Goldberg as to the legality of the
                          securities being registered.

    23.1                  Consent of independent auditors.

    23.2                  Consent of David Goldberg (included in Exhibit 5.1).

    99.1                  The Company's 1997 Stock Option and Incentive Plan.