Exhibit 5.1

                                December 3, 1998


AMB Property Corporation
505 Montgomery Street
San Francisco, California 94111

      Re:   AMB Property Corporation, a Maryland corporation (the "Company")-
            Registration Statement on Form S-3 pertaining to the issuance of up
            to 2,542,163 shares (the "Shares") of common stock of the Company,
            par value $.01 per share (the "Common Stock")filed on or about
            December 2, 1998

Ladies and Gentlemen:

      You have requested our opinion, as special Maryland corporate counsel to
AMB Property Corporation, a Maryland corporation (the "Company"), with respect
to the matters set forth below in connection with the registration of the
issuance and resale of the Shares, covered by the above-referenced Registration
Statement (the "Registration Statement"), filed by the Company with the
Securities and Exchange Commission (the "Commission") under the Securities Act
of 1933, as amended (the "Act"). The Shares are to be issued in exchange for up
to 2,542,163 units of limited partnership interest (the "Units") in AMB
Property, L.P., a Delaware limited partnership (the "Operating Partnership").
Unless otherwise defined herein, capitalized terms used herein shall have the
meanings assigned to them in the Registration Statement.

      In our capacity as special Maryland corporate counsel to the Company, and
as a basis for the opinion hereinafter set forth, we have examined originals, or
copies certified or otherwise identified to our satisfaction, of the following
documents (collectively, the "Documents"): 

     (i) The Registration Statement and the related form of prospectus (the
"Prospectus") included therein in the form in which it was transmitted to the
Commission under the Act; 

     (ii) The charter of the Company (the "Charter"), consisting of Articles of
Incorporation filed with the Maryland State Department of Assessments and
Taxation (the "Department") on November 24, 1997, and Articles Supplementary
filed on July 23, 1998, November 12, 1998, and November 25, 1998; 

     (iii) The Bylaws of the Company (the "Bylaws"), which were duly adopted by
the Board of Directors of the Company on November 24, 1997;

     (iv) Certain resolutions adopted and actions taken by the Board of
Directors of the Company (the "Board of Directors") on or before the date hereof
and in full force and effect on the date hereof including, but not limited to,
those certain resolutions adopted by the Board of Directors on November 24, 1997
relating to the sale, issuance and registration of the Shares, certified as of a
recent date by an officer of the Company (the "Resolutions"); 

     (v) A status certificate of recent date issued by the Department to the
effect that the Company is duly incorporated and existing under the laws of the
State of Maryland; 

     (vi) The form of certificate representing a share of Common Stock,
certified as of a recent date by an officer of the Company; 

     (vii) The Third Amended and Restated Partnership Agreement of the Operating
Partnership certified as of a recent date by an Officer of the Company (the
"Partnership Agreement"); 

     (viii) A Certificate of Officers of the Company of recent date to the
effect that, among other things, the Charter and Bylaws of the Company and the
resolutions and actions by the Board of Directors which we have examined are
true, correct and complete, have not been rescinded or modified and are in full
force and effect on the date of such certificate; and

     (ix) Such other documents and matters as we have deemed necessary or
appropriate to express the opinion set forth in this letter, subject to the
assumptions, limitations and qualifications stated herein.
AMB Property Corporation
December 3, 1998
Page 2

      In expressing the opinion set forth below, we have assumed, and so far as
is known to us there are no facts inconsistent with, the following: 

     (a) Each of the parties (other than the Company) executing any of the
Documents has duly and validly executed and delivered each of the Documents to
which such party is a signatory, and such party's obligations set forth therein
are legal, valid and binding; 

     (b) Each individual executing any of the Documents on behalf of a party
(other than the Company) is duly authorized to do so; 

     (c) Each individual executing any of the Documents, whether on behalf of
such individual or another person, is legally competent to do so; 

     (d) All Documents submitted to us as originals are authentic. The form and
content of the Documents submitted to us as unexecuted drafts do not differ in
any respect relevant to this opinion from the form and content of such Documents
as executed and delivered. All Documents submitted to us as certified or
photostatic copies conform to the original documents. All signatures on all such
Documents are genuine. All public records reviewed or relied upon by us or on
our behalf are true and complete. All statements and information contained in
the Documents are true and complete. There are no modifications of or amendments
to the Documents, and there has been no waiver of any of the provisions of the
Documents, by action or omission of the parties or otherwise; 

     (e) The Resolutions adopted and the actions taken and to be taken by the
Board of Directors including, but not limited to, the adoption of all
resolutions and the taking of all action necessary to authorize the issuance and
sale of the Shares have occurred at duly called meetings at which a quorum of
the incumbent directors of the Company were or are present and acting
throughout, or by unanimous written consent of all incumbent directors, all in
accordance with the Charter and Bylaws of the Company and applicable law; and


     (f) The number of shares of Common Stock to be offered and sold under the
Registration Statement will not, in the aggregate, exceed the number of shares
of Common Stock authorized in the Charter of the Company, less the number of
shares of Common Stock authorized and reserved for issuance and/or issued and
outstanding on the date on which the Shares are authorized or the date on which
the Shares are issued and delivered, and none of the Shares will be issued, sold
or transferred in violation of the provisions of the Charter of the Company. 

     The phrase "known to us" is limited to the actual knowledge, without
independent inquiry, of the lawyers at our firm who have performed legal
services in connection with the issuance of this opinion.

      Based upon the foregoing, and subject to the assumptions, limitations and
qualifications stated herein, it is our opinion that:

      1.    The Company is a corporation duly incorporated and existing under
            and by virtue of the laws of the State of Maryland and is in good
            standing with the SDAT.

      2.    The Shares are duly authorized and, upon issuance in accordance with
            the Prospectus, the Resolutions, the Partnership Agreement and the
            Charter, and upon due execution, countersignature and delivery of
            certificates representing the Shares, when and if delivered against
            payment of the consideration therefor as set by the Board of
            Directors, the Shares will be validly issued, fully paid and
            nonassessable.

      We consent to the filing of this opinion as an exhibit to the Registration
Statement and further consent to the filing of this opinion as an exhibit to
applications to the securities commissioners of the various states of the United
States for registration of the Securities. We also consent to the identification
of our firm as Maryland counsel to the Company in the section of the Prospectus
(which is a part of the Registration Statement) entitled "Legal Matters." In
giving these consents, we do not admit that we are within the category of
persons whose consent is required by Section 7 of the Act.

      This opinion is limited to the present corporate laws of the State of
Maryland and we express no opinion with respect to the laws of any other
jurisdiction. Furthermore, the opinions presented in this letter are limited to
the

AMB Property Corporation
December 3, 1998
Page 3

matters specifically set forth herein and no other opinion shall be inferred
beyond the matters expressly set forth herein. Without limiting the generality
of the foregoing, we express no opinion with respect to any securities laws or
with respect to the action required for the Operating Partnership to authorize,
execute or deliver any of the Units or any other document, instrument or
agreement.

      The opinions set forth in this letter are rendered as of the date hereof
and are necessarily limited to laws now in effect and facts and circumstances
presently existing and brought to our attention. We assume no obligation to
supplement this opinion if any applicable law is changed after the date hereof
or if we become aware of any facts or circumstances which now exist or which
occur or arise in the future and may change the opinions expressed herein after
the date hereof.

      The opinions expressed in this letter are for your use and the use of your
securities counsel, Latham & Watkins, in connection with the filing of the
Registration Statement and the rendering of opinions by Latham & Watkins in
connection therewith, and may not be relied upon by you or Latham & Watkins for
any other purpose, without our prior written consent.

                                    Very truly yours,

                                    /s/ BALLARD SPAHR ANDREWS & INGERSOLL, LLP