EXHIBIT 5.1
                                  May 12, 2000


AMB Property Corporation
505 Montgomery Street
San Francisco, California 94111


               Re: Registration Statement on Form S-3

Ladies and Gentlemen:

               We have served as special Maryland corporate counsel to AMB
Property Corporation, a Maryland corporation (the "Company"), in connection with
the registration with the Securities and Exchange Commission (the "Commission")
of up to Six Hundred Four Thousand Four Hundred Thirty-Three (604,433) shares of
common stock, par value $.01 per share (the "Shares"), of the Company covered by
the Registration Statement (as defined herein). The Shares are to be issued by
the Company upon the exchange of units of limited partnership interest (the
"Units") of AMB Property, L.P., a Delaware limited partnership (the
"Partnership"), of which the Company is general partner, in accordance with the
Agreement of Limited Partnership of AMB Property, L.P., as amended to date (the
"Partnership Agreement").

               In connection with our representation of 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 on Form S-3 (the "Registration
Statement"), in substantially the form filed or to be filed by the Company with
the Commission under the Securities Act of 1933, as amended (the "1933 Act"),
and the related form of prospectus, all relating to the possible resale or
issuance and resale of the Shares;

               ii. The charter of the Company (the "Charter"), certified as of a
recent date by the State Department of Assessments and Taxation of Maryland (the
"SDAT");

               iii. The Bylaws of the Company, certified as of a recent date by
an officer of the Company;

               iv. Resolutions adopted by the Board of Directors of the Company,
or a duly authorized committee thereof (the "Directors' Resolutions"),
authorizing, among other things, the Company, on its own behalf and on behalf of
the Partnership, as its general partner, to cause


AMB Property Corporation
May __, 2000
Page 2

the Partnership to issue the Units, to issue the Shares in exchange for the
Units, and to file the Registration Statement;

               v. A certificate as of a recent date of the SDAT as to the good
standing of the Company;

               vi. The form of certificate evidencing a Share, certified as of a
recent date by an officer of the Company;

               vii. The Partnership Agreement;

               viii. A certificate executed by an officer of the Company, dated
as of a recent date;

               ix. One or more contribution agreements, by and among the
Company, the Partnership and the Selling Stockholders named in the Registration
Statement; and

               x. 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.

               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:

               1. Each individual executing any of the Documents, whether on
behalf of such individual or another person, is legally competent to do so.

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

               3. 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 and are enforceable in accordance with all
stated terms.

               4. Any Documents submitted to us as originals are authentic. The
form and content of any 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. Any Documents submitted to us as certified
or photostatic copies conform to the original documents. All signatures on all
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 has been no modification of or
amendment to any of the Documents, and there has been no waiver of any provision
of any of the Documents, by action or omission of the parties or otherwise.


AMB Property Corporation
May __, 2000
Page 3

               5. The Units have been and are validly issued units of limited
partnership interest in the Partnership, and the Units are not and have not
been, nor are or will the Shares be, issued in violation of any restriction or
limitation contained in the Charter.

               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 formed 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 have been duly authorized for issuance and, when
and if issued and delivered against tender of the Units for exchange in
accordance with the Partnership Agreement and the Directors' Resolutions, will
be validly issued, fully paid and nonassessable.

               The foregoing opinion is limited to the substantive laws of the
State of Maryland and we do not express any opinion herein concerning any other
law. We express no opinion as to the applicability or effect of any federal or
state securities laws, including the securities laws of the State of Maryland,
or as to federal or state laws regarding fraudulent transfers. To the extent
that any matter as to which our opinion is expressed herein would be governed by
any jurisdiction other than the State of Maryland, we do not express any opinion
on such matter.

               We assume no obligation to supplement this opinion if any
applicable law changes after the date hereof or if we become aware of any fact
that might change the opinion expressed herein after the date hereof.

               This opinion is being furnished to you for submission to the
Commission as an exhibit to the Registration Statement. We consent to the filing
of this opinion as an exhibit to the Registration Statement and to the use of
the name of our firm in the section entitled "Legal Matters" in the Registration
Statement. In giving this consent, we do not admit that we are within the
category of persons whose consent is required by Section 7 of the 1933 Act.

                                Very truly yours,


                                /s/  Ballard, Spahr, Andrews & Ingersoll, LLP