Exhibit 2.2

                                SECOND AMENDMENT

                                       TO

               AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT

                                       OF

                        CORPORATE OFFICE PROPERTIES, L.P.

         THIS AMENDMENT (this "Amendment"), dated October 13, 1998, pertains to
that certain Amended and Restated Limited Partnership Agreement, dated as of
March 16, 1998, as amended by that certain First Amendment to Amended and
Restated Limited Partnership Agreement, dated as of September 28, 1998
(collectively, the "Partnership Agreement"), of CORPORATE OFFICE PROPERTIES,
L.P., a Delaware limited partnership (the "Partnership"). Capitalized terms used
herein but not defined herein shall have the meanings given to such terms in the
Partnership Agreement.

                                   BACKGROUND

         The Partnership, by assignment from its affiliate COPT ACQUISITIONS,
INC., is a party to that certain Contribution Agreement dated as of September
30, 1998 (the "Contribution Agreement") pursuant to which, among other things,
the Partnership has agreed to acquire certain real and personal property owned
by M.O.R. XXIX ASSOCIATES LIMITED PARTNERSHIP, a Maryland limited partnership
("Contributor"), in consideration for, among other things, Partnership Interests
in the Partnership. Pursuant to Sections 8.7 and 11.1(B) of the Partnership
Agreement, the General Partner of the Partnership has the power and authority to
admit any Person making a Capital Contribution as an Additional Limited Partner.
The General Partner, pursuant to the exercise of such authority and in
accordance with Sections 8.8 of the Partnership Agreement, has determined to
execute this Amendment to evidence the issuance of additional Partnership
Interests and the admission of Contributor as a Limited Partner of the
Partnership.

         NOW, THEREFORE, the parties hereto, for good and sufficient
consideration and intending to be legally bound, hereby amend the Partnership
Agreement as follows;

         1. The Partnership Agreement is hereby amended to reflect the admission
of Contributor as a Limited Partner on the date hereof.

         2. The Partnership shall issue to Contributor the number of Partnership
Units contemplated by the Contribution Agreement. The Partnership Interests
evidenced by the Partnership Units issued hereby shall have the same rights,
preferences, privileges and designations as the Limited Partner Partnership
Interests which have heretofore been issued by the Partnership, including, but
not limited to, the right to redeem such Partnership Interests in accordance
with Article IX of the Partnership Agreement.





         3. By execution of this Amendment, Contributor agrees to be bound by
each and every term of the Partnership Agreement, as amended hereby, from and
after the date hereof, including, but not limited to, Section 12.3 of the
Partnership Agreement.

         4. Except as expressly set forth in this Amendment, the Partnership
Agreement is hereby ratified and confirmed in each and every respect.

                                       2




                    (signatures continued from previous page)

                  IN WITNESS WHEREOF, this Amendment is executed and delivered
as of the date first written above.

                              General Partner:

                              CORPORATE OFFICE PROPERTIES TRUST, a
                              Maryland real estate investment trust

                              By: 
                                 -------------------------------
                              Name: Randall M. Griffin
                              Its:  President

                              Contributor:

                              M.O.R. XXIX ASSOCIATES LIMITED PARTNERSHIP, 
                              a Maryland limited partnership

                              By:  RA & DM, Inc., a Maryland corporation, its 
                                   general partner

                              By:    
                                 -------------------------------
                              Name:  Richard M. Alter
                              Its:   President

                                       3