Exhibit 1.2

                             ARTICLES SUPPLEMENTARY
                                       OF

                        CORPORATE OFFICE PROPERTIES TRUST
                 SERIES E CUMULATIVE REDEEMABLE PREFERRED SHARES
                           (PAR VALUE $.01 PER SHARE)

     CORPORATE OFFICE PROPERTIES TRUST, a Maryland real estate investment trust
(hereinafter called the "Trust"), having its principal office in Columbia,
Maryland, hereby certifies to the Department of Assessments and Taxation of the
State of Maryland that:

     FIRST: Pursuant to authority expressly vested in the Board of Trustees of
the Trust by Article VI of the Declaration of Trust of the Trust, as amended to
date (the "Declaration of Trust"), the Board of Trustees has duly classified
1,265,000 authorized but unissued preferred shares of beneficial interest of the
Trust, par value $.01 per share (the "Preferred Shares"), into a class
designated as 10.25% Series E Cumulative Redeemable Preferred Shares, par value
$.01 per share, and has provided for the issuance of such class by adoption of a
resolution in the form of Article Third hereof effective as of March 15, 2001.

     SECOND: The classification increases the number of shares classified as
     10.25% Series E Cumulative Redeemable Preferred Shares, par value $.01 per
     share, from no shares immediately prior to the classification to 1,265,000
     shares immediately after the classification. The classification decreases
     the number of unclassified Preferred Shares from 1,440,307 to 175,307.


     THIRD: The terms of the 10.25% Series E Cumulative Redeemable Preferred
Shares (including the preferences, conversion or other rights, voting powers,
restrictions, limitations as to dividends and other distributions,
qualifications, or terms or conditions of redemption) as set by the Board of
Trustees are as follows:

     1.   NUMBER OF SHARES AND DESIGNATION.

     This series of Preferred Shares shall be designated as 10.25% Series E
Cumulative Redeemable Preferred Shares, par value $.01 per share (the "Series E
Preferred Shares"), and 1,265,000 shares shall be the authorized number of such
Series E Preferred Shares constituting such series.

     2.   DEFINITIONS.

     For purposes of the Series E Preferred Shares, the following terms shall
have the meanings indicated:


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          "Affiliate" of a Person means a Person that directly, or indirectly
     through one or more intermediaries, controls or is controlled by, or is
     under common control with, the Person specified.

               "Board of Trustees" shall mean the Board of Trustees of the Trust
          or any committee authorized by such Board of Trustees to perform any
          of its responsibilities with respect to the Series E Preferred Shares;
          provided that, for purposes of paragraph (a) of Section 8 of this
          Article, the term "Board of Trustees" shall not include any such
          committee.

               "Business Day" shall mean any day other than a Saturday, Sunday
          or a day on which state or federally chartered banking institutions in
          New York, New York are not required to be open.

               "Code" shall mean the Internal Revenue Code of 1986, as amended
          from time to time, or any successor statute thereto. Reference to any
          provision of the Code shall mean such provision as in effect from time
          to time, as the same may be amended, and any successor thereto, as
          interpreted by any applicable regulations or other administrative
          pronouncements as in effect from time to time.

     "Common Shares" shall mean the common shares of beneficial interest, $.01
par value per share, of the Trust.

     "Declaration of Trust" shall mean the Amended and Restated Declaration of
Trust of the Trust as filed for record with the State Department of Assessments
and Taxation of Maryland, and any amendments thereto.

     "Dividend Payment Date" shall mean January 15, April 15, July 15 and
October 15 of each year; provided, that if any Dividend Payment Date falls on
any day other than a Business Day, the dividend payment payable on such Dividend
Payment Date shall be paid on the Business Day immediately following such
Dividend Payment Date and no interest shall accrue on such dividend from such
date to such Dividend Payment Date.

     "Dividend Periods" shall mean the Initial Dividend Period and each
subsequent quarterly dividend period commencing on and including January 15,
April 15, July 15 and October 15 of each year and ending on and including the
day preceding the first day of the next succeeding Dividend Period, other than
the Dividend Period during which any Series E Preferred Shares shall be redeemed
pursuant to Section 5 hereof, which shall end on and include the Redemption Date
with respect to the Series E Preferred Shares being redeemed.

     "Dividend Record Date" shall have the meaning set forth in paragraph (a) of
Section 3 of this Article.


                                       10


     "Equity Shares" shall mean shares of any class or series of shares of
beneficial ownership in the Trust.

     "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended.

     "Initial Dividend Period" shall mean the period commencing on and including
the Issue Date and ending on and including July 14, 2001.

     "Issue Date" shall mean the date of original issuance of the Series E
Preferred Shares.

     "Junior Shares" shall have the meaning set forth in paragraph (a) of
Section 7 of this Article.

     "Liquidation Preference" shall have the meaning set forth in paragraph (a)
of Section 4 of this Article.

     "Operating Partnership" shall mean Corporate Office Properties, L.P., a
Delaware limited partnership.

     "Parity Shares" shall have the meaning set forth in paragraph (b) of
Section 7 of this Article.

     "Person" shall mean an individual, corporation, partnership, estate, trust
(including a trust qualifying under Section 401(a) or 501(c)(17) of the Code), a
portion of a trust permanently set aside for or to be used exclusively for the
purposes described in Section 642(c) of the Code, association, "private
foundation," within the meaning of Section 509(a) of the Code, joint stock
company or other entity, and also includes a "group," as that term is used for
purposes of Section 13(d)(3) of the Exchange Act, and a group to which an
Excepted Holder limit applies.

     "Redemption Date" shall mean, in the case of any redemption of any Series E
Preferred Shares, the date fixed for redemption of such shares.

     "Redemption Notice" shall have the meaning set forth in paragraph (d) of
Section 5 of this Article.

     "Redemption Price" shall mean, with respect to any Series E Preferred
Shares to be redeemed, a cash payment equal to 100% of the Liquidation
Preference thereof plus, all accrued and unpaid dividends, if any, to the
Redemption Date.

     "REIT" shall mean a "real estate investment trust," as defined in Section
856 of the Code.

     "Senior Shares" shall have the meaning set forth in paragraph (c) of
Section 7 of this Article.

     "Series A Preferred Shares" shall mean the Trust's 5.5% Series A
Convertible Preferred


                                       11


Shares of beneficial interest, par value $.01 per share.

     "Series B Preferred Shares" shall meaning the Trust's 10% Series B
Cumulative Redeemable Shares of beneficial interest, par value $.01 per share.

     "Series D Preferred Shares" shall mean the Trust's 4% Series D Cumulative
Convertible Redeemable Preferred Shares of beneficial interest, par value $.01
per share.

     "Set apart for payment" shall be deemed to include, without any action
other than the following, the recording by the Trust in its accounting ledgers
of any accounting or bookkeeping entry which indicates, pursuant to a
declaration of dividends or other distribution by the Board of Trustees, the
allocation of funds to be so paid on any series or class of Equity Shares of the
Trust; provided, however, that if any funds for any class or series of Junior
Shares or any class or series of Parity Shares are placed in a separate account
of the Trust or delivered to a disbursing, paying or other similar agent, then
"set apart for payment" with respect to the Series E Preferred Shares shall mean
placing such funds in a separate account or delivering such funds to a
disbursing, paying or other similar agent.

     "Transfer Agent" means Norwest Bank or such transfer agent as may be
designated from time to time by the Board of Trustees or its designee as the
transfer agent for the Series E Preferred Shares.

     "Trustee" shall mean a member of the Board of Trustees.

               "Voting Parity Shares" shall have the meaning set forth in
          paragraph (a) of Section 8 of this Article.


     3.   DIVIDENDS.

     (a) The holders of Series E Preferred Shares shall be entitled to receive,
when, as and if declared by the Board of Trustees, out of funds legally
available for that purpose, quarterly cash dividends on the Series E Preferred
Shares at the rate of 10.25% of the Liquidation Preference per year (equivalent
to $2.625 per year per Series E Preferred Share). Such dividends shall be
cumulative from the Issue Date, whether or not in any Dividend Period or
Periods such dividends shall be declared or there shall be funds of the Trust
legally available for the payment of such dividends, and shall be payable
quarterly in arrears on each Dividend Payment Date, commencing on July 15,
2001. Each such dividend shall be payable in arrears to the holders of record
of the Series E Preferred Shares, as they appear on the share records of the
Trust at the close of business on the applicable record date (the "DIVIDEND
RECORD DATE"), which shall be fixed by the Board of Trustees and which shall
be not more than 60 days nor less than 10 days prior to each such Dividend
Payment Date. The Dividend Record Date for the dividend payable on July 15,
2001 shall be June 30, 2001. Accrued and unpaid dividends for any past
Dividend Periods may be declared and paid at any time, without reference to
any regular Dividend Payment Date, to holders of record on such date, which
date shall not precede by more than 45 days nor less than 15 days the payment
date thereof, as may be fixed by the Board of Trustees.

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     (b) Any dividend payable on the Series E Preferred Shares for any partial
Dividend Period shall be computed ratably on the basis of twelve 30-day months
and a 360-day year. Holders of Series E Preferred Shares shall not be entitled
to any dividends in excess of full cumulative dividends, as herein provided, on
the Series E Preferred Shares. No interest, or sum of money in lieu of interest,
shall be payable in respect of any dividend payment or payments on the Series E
Preferred Shares that may be in arrears.

     (c) So long as any of the Series E Preferred Shares are outstanding, when
dividends are not paid in full upon the Series E Preferred Shares or any other
class or series of Parity Shares, or a sum sufficient for such payment is not
set apart for payment, all dividends declared upon the Series E Preferred Shares
and any Parity Shares shall be declared ratably in proportion to the respective
amounts of dividends accrued and unpaid on the Series E Preferred Shares and
accrued and unpaid on such Parity Shares. Except as set forth in the preceding
sentence, unless dividends on the Series E Preferred Shares equal to the full
amount of accrued and unpaid dividends have been or contemporaneously are
declared and paid or declared and a sum sufficient for the payment thereof has
been or contemporaneously is set apart for such payment, for all past dividends
periods, no dividends shall be declared or paid or set apart for payment by the
Trust and no other distribution of cash or other property may be declared or
made, directly or indirectly, by the Trust with respect to any Parity Shares.

     (d) So long as any of the Series E Preferred Shares are outstanding, unless
dividends equal to the full amount of all accrued and unpaid dividends on the
Series E Preferred Shares have been paid, or declared and set apart for payment,
for all past dividend periods, no dividends (other than dividends or
distributions paid in Junior Shares or options, warrants or rights to subscribe
for or purchase Junior Shares) may be declared or paid or set apart for payment
by the Trust and no other distribution of cash or other property may be declared
or made, directly or indirectly, by the Trust with respect to any Junior Shares,
nor shall any Junior Shares be redeemed, purchased or otherwise acquired (except
for a redemption, purchase or other acquisition of Common Shares made for
purposes of an employee incentive or benefit plan of the Trust or a subsidiary
of the Trust) for any consideration (or any monies be paid to or made available
for a sinking fund for the redemption of any such Junior Shares), directly or
indirectly, by the Trust (except by conversion into or exchange for Junior
Shares, or options, warrants or rights to subscribe for or purchase Junior
Shares), nor shall any other cash or other property be paid or distributed to or
for the benefit of holders of Junior Shares.

     (e) Notwithstanding the provisions of this Section 3, the Trust shall not
be prohibited from (i) declaring or paying or setting apart for payment any
dividend or distribution on any Parity Shares or (ii) redeeming, purchasing or
otherwise acquiring any Parity Shares, in each case, if such declaration,
payment, redemption, purchase or other acquisition is necessary in order to
maintain the continued qualification of the Trust as a REIT under Section 856 of
the Code.

     4.   LIQUIDATION PREFERENCE.

     (a) Upon any voluntary or involuntary liquidation, dissolution or
     winding-up of the Trust, before any payment or distribution by the Trust
     shall be made to or set apart for payment


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     to the holders of any Junior Shares, the holders of Series E Preferred
     Shares shall be entitled to receive a liquidation preference of Twenty-Five
     Dollars ($25.00) per Series E Preferred Share (the "LIQUIDATION
     PREFERENCE"), plus an amount equal to all accrued and unpaid dividends
     (whether or not earned or declared) to the date of final distribution to
     such holders; but such holders shall not be entitled to any further
     payment. Until the holders of the Series E Preferred Shares have been paid
     the Liquidation Preference in full, plus an amount equal to all accrued and
     unpaid dividends (whether or not earned or declared) to the date of final
     distribution to such holders, no payment will be made to any holder of
     Junior Shares upon the liquidation, dissolution or winding-up of the Trust.
     If, upon any liquidation, dissolution or winding-up of the Trust, the
     assets of the Trust, or proceeds thereof, distributable among the holders
     of Series E Preferred Shares shall be insufficient to pay in full the
     Liquidation Preference and liquidating payments on any other shares of any
     class or series of Parity Shares, then such assets, or the proceeds
     thereof, shall be distributed among the holders of Series E Preferred
     Shares and any such other Parity Shares ratably in the same proportion as
     the respective amounts that would be payable on such Series E Preferred
     Shares and any such other Parity Shares if all amounts payable thereon were
     paid in full. For the purposes of this Section 4, a voluntary or
     involuntary liquidation, dissolution or winding-up of the Trust shall not
     include (i) a consolidation or merger of the Trust with or into one or more
     other entities, (ii) a sale or transfer of all or substantially all of the
     Trust's assets, or (iii) a statutory share exchange.

     (b) Upon any liquidation, dissolution or winding-up of the Trust, after
payment shall have been made in full to the holders of Series E Preferred Shares
and any Parity Shares, as provided in Section 4(a), any other series or class or
classes of Junior Shares shall, subject to the respective terms thereof, be
entitled to receive any and all assets remaining to be paid or distributed, and
the holders of the Series E Preferred Shares and any Parity Shares shall not be
entitled to share therein.

     5.   REDEMPTION AT THE OPTION OF THE TRUST.

     (a) Series E Preferred Shares shall not be redeemable by the Trust prior to
July 15, 2006, except as set forth in Article VII of the Declaration of Trust
which is incorporated by reference herein. On or after July 15, 2006, the Trust,
at its option, may redeem Series E Preferred Shares, in whole or from time to
time in part, at the Redemption Price. The Redemption Price of the Series E
Preferred Shares (other than any portion thereof consisting of accrued and
unpaid dividends) shall be payable solely with the proceeds from the sale by the
Trust or the Operating Partnership of equity securities of the Trust or the
Operating Partnership (whether or not such sale occurs concurrently with such
redemption). For purposes of the preceding sentence, "equity securities" shall
include any Common Shares, preferred shares, depositary shares, partnership or
other interests, participations or other ownership interests (however
designated) and any rights (other than debt securities convertible into or
exchangeable at the option of the holder for equity securities of the Trust
(unless and to the extent such debt securities are subsequently converted into
such equity securities)) or options to purchase any of the foregoing of or in
the Trust or the Operating Partnership.

     (b) In the event of a redemption of Series E Preferred Shares, if the
Redemption Date


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occurs after a Dividend Record Date and on or prior to the related Dividend
Payment Date, the dividend payable on such Dividend Payment Date in respect of
such shares called for redemption shall be payable on such Dividend Payment Date
to the holders of record at the close of business on such Dividend Record Date
and shall not be payable as part of the Redemption Price for such shares. If
full cumulative dividends on all outstanding Series E Preferred Shares have not
been paid or declared and set apart for payment, no Series E Preferred Shares
may be redeemed unless all outstanding Series E Preferred Shares are
simultaneously redeemed and neither the Trust nor any Affiliate of the Trust may
purchase or acquire Series E Preferred Shares, otherwise than pursuant to a
purchase or exchange offer made on the same terms to all holders of Series E
Preferred Shares.

     (c) If fewer than all the outstanding Series E Preferred Shares are to be
     redeemed, the Trust will select those Series E Preferred Shares to be
     redeemed pro rata in proportion to the numbers of Series E Preferred Shares
     held by holders (with adjustment to avoid redemption of fractional shares)
     or by lot or in such other manner as the Board of Trustees may determine.
     If fewer than all Series E Preferred Shares represented by any certificate
     are redeemed, then a new certificate representing the unredeemed Series E
     Preferred Shares shall be issued without cost to the holders thereof.


     (d) If the Trust shall redeem Series E Preferred Shares pursuant to
paragraph (a) of this Section 5, notice of the redemption will be given by
publication in a newspaper of general circulation in the City of New York, such
publication to be made once a week for two consecutive weeks commencing not less
than 30 nor more than 60 days prior to the Redemption Date. A similar notice of
such redemption shall be mailed by the Trust not less than 30 days nor more than
60 days prior to the Redemption Date to each holder of record of the Series E
Preferred Shares to be redeemed (the "REDEMPTION NOTICE"). Such Redemption
Notice shall be provided by first class mail, postage prepaid, at such holder's
address as the same appears on the share records of the Trust. Neither the
failure to mail the Redemption Notice, nor any defect therein or in the mailing
thereof to any particular holder, shall affect the sufficiency of the Redemption
Notice or the validity of the proceedings for redemption with respect to the
other holders. A Redemption Notice which has been mailed in the manner herein
provided shall be conclusively presumed to have been duly given on the date
mailed whether or not the holder receives the Redemption Notice. Each Redemption
Notice shall state, as appropriate: (i) the Redemption Date; (ii) the number of
Series E Preferred Shares to be redeemed; (iii) the place or places where
certificates for such Series E Preferred Shares are to be surrendered; and (iv)
the Redemption Price payable on such Redemption Date, including, without
limitation, a statement as to whether or not accrued and unpaid dividends will
be (x) payable as part of the Redemption Price, or (y) payable on the next
Dividend Payment Date to the record holder at the close of business on the
relevant Record Date as described in the next succeeding sentence. A Redemption
Notice having been mailed as aforesaid, from and after the Redemption Date
(unless the Trust shall fail to make available the amount of cash necessary to
effect such redemption), (i) dividends on the Series E Preferred Shares so
called for redemption shall cease to accrue on said shares, (ii) said shares
shall no longer be deemed to be outstanding, and (iii) all rights of the holders
thereof as holders of Series E Preferred Shares shall cease, except (a) the
right to receive the Redemption Price, without interest thereon, and (b) if the
Redemption Date for any Series E Preferred Shares occurs after any Dividend
Record Date and on or prior to the related Dividend


                                       15


Payment Date, the full dividend payable on such Dividend Payment Date in respect
of such Series E Preferred Shares called for redemption shall be payable on such
Dividend Payment Date to the holders of record of such shares at the close of
business on the corresponding Dividend Record Date notwithstanding the prior
redemption of such shares. The Trust's obligation to make available the cash
necessary to effect such redemption in accordance with the preceding sentence
shall be deemed fulfilled if, on or before the applicable Redemption Date, the
Trust shall irrevocably deposit in trust with a bank or trust company (which may
not be an Affiliate of the Trust) that has, or is an Affiliate of a bank or
trust company that has, a capital and surplus of at least $50,000,000, such
amount of cash as is necessary for such redemption plus, if such Redemption Date
occurs after any Dividend Record Date and on or prior to the related Dividend
Payment Date, such amount of cash as is necessary to pay the dividend payable on
such Dividend Payment Date in respect of such Series E Preferred Shares called
for redemption, with irrevocable instructions that such cash be applied to the
redemption of the Series E Preferred Shares so called for redemption and, if
applicable, the payment of such dividend. No interest shall accrue for the
benefit of the holders of Series E Preferred Shares to be redeemed on any cash
so set aside by the Trust. Subject to applicable escheat laws, any such cash
unclaimed at the end of two years from the Redemption Date shall revert to the
general funds of the Trust, after which reversion the holders of Series E
Preferred Shares so called for redemption shall look only to the general funds
of the Trust for the payment of such cash. As promptly as practicable after the
surrender in accordance with the Redemption Notice of the certificates for any
such Series E Preferred Shares to be so redeemed (properly endorsed or assigned
for Transfer, if the Trust shall so require and the Redemption Notice shall so
state), such certificates shall be exchanged for cash (without interest thereon)
for which such Series E Preferred Shares have been redeemed in accordance with
such Redemption Notice.

     6.   STATUS OF REACQUIRED SHARES.

     All Series E Preferred Shares that have been issued and are reacquired in
any manner by the Trust (including, without limitation, Series E Preferred
Shares which are redeemed) shall be returned to the status of authorized but
unissued Series E Preferred Shares.

     7.   RANKING.

The Series E Preferred Shares will, with respect to dividend rights and rights
upon the liquidation, dissolution or winding-up of the Trust, rank:


     (a) prior or senior to the Common Shares and any other class or series of
our Equity Shares authorized or designated in the future if the holders of
Series E Preferred Shares shall be entitled to the receipt of dividends or of
amounts distributable upon liquidation, dissolution or winding-up in preference
or priority to the holders of shares of such class or series ("JUNIOR SHARES");

     (b) on a parity with the Series A Preferred Shares, the Series B Preferred
Shares, the Series D Preferred Shares, and any other class or series of our
Equity Shares authorized or designated in the future if the holders of such
class or series of securities and the Series E Preferred Shares shall be
entitled to the receipt of dividends and of amounts distributable upon


                                       16


liquidation, dissolution or winding-up in proportion to their respective amounts
of accrued and unpaid dividends per share or liquidation preferences, without
preference or priority of one over the other ("PARITY SHARES"); and

     (c) junior to any class or series of our Equity Shares authorized or
designated in the future if the holders of such class or series shall be
entitled to the receipt of dividends and amounts distributable upon liquidation,
dissolution or winding-up in preference or priority to the holders of the Series
E Preferred Shares ("SENIOR SHARES").

     8.   VOTING.

     (a) If and whenever six quarterly dividends (whether or not consecutive)
payable on the Series E Preferred Shares or any series or class of Parity Shares
shall be in arrears (which shall, with respect to any such quarterly dividend,
mean that any such dividend has not been paid in full), whether or not declared,
the number of Trustees then constituting the Board of Trustees shall be
increased by two (if not already increased by reason of similar types of
provisions with respect to Parity Shares of any other class or series which is
entitled to similar voting rights, other than the Series A Preferred Shares (the
"VOTING PARITY SHARES")) and the holders of Series E Preferred Shares, together
with the holders of all other Voting Parity Shares then entitled to exercise
similar voting rights, voting as a single class regardless of series, shall be
entitled to elect the two additional Trustees to serve on the Board of Trustees
at any annual meeting of shareholders or at a special meeting of the holders of
the Series E Preferred Shares and the Voting Parity Shares called as hereinafter
provided. At any time when such right to elect Trustees separately shall have
been so vested in the holders of Series B Preferred Shares and the Voting Parity
Shares, if applicable, the Secretary of the Trust may, and upon the written
request of the holders of record of not less than 20% of the total number of
Series E Preferred Shares and Voting Parity Shares (addressed to the Secretary
at the principal office of the Trust) shall, call a special meeting of the
holders of the Series E Preferred Shares and of the Voting Parity Shares for the
election of the two Trustees to be elected by them as herein provided, such call
to be made by notice similar to that provided in the Bylaws of the Trust for a
special meeting of the shareholders or as required by law. Such special meeting
shall be held, in the case of such written request, within 90 days after the
delivery of such request, provided that the Trust shall not be required to call
such a special meeting if such request is received less than 120 days before the
date fixed for the next ensuing annual meeting of shareholders and the holders
of the Series E Preferred Shares and Voting Parity Share are offered the
opportunity to elect such Trustees at such annual meeting. The Trustees elected
at any such special meeting shall hold office until the next annual meeting of
the shareholders or special meeting held in lieu thereof if such office shall
not have previously terminated as provided herein. If any vacancy shall occur
among the Trustees elected by the holders of the Series E Preferred Shares and
the Voting Parity Shares by reason of death, resignation or disability, a
successor shall be elected by the Board of Trustees, upon the nomination of the
then-remaining Trustee elected by the holders of the Series E Preferred Shares
and the Voting Parity Shares or the successor of such remaining Trustee, to
serve until the next annual meeting of the shareholders or special meeting held
in place thereof if such office shall not have previously terminated as provided
above. Whenever all arrears in dividends on the Series E Preferred Shares and
the Voting Parity Shares then outstanding shall have been paid and dividends
thereon for the current Dividend Period shall have been declared


                                       17


and paid, or declared and set apart for payment, then the right of the holders
of the Series E Preferred Shares and the Voting Parity Shares to elect such
additional two Trustees shall cease (but subject always to the same provision
for the vesting of such voting rights in the case of any similar future
arrearages), and the terms of office of all persons elected as Trustees by the
holders of the Series E Preferred Shares and the Voting Parity Shares shall
forthwith terminate and the number of Trustees constituting the Board of
Trustees shall be reduced accordingly.

     (b) So long as any Series E Preferred Shares are outstanding, in addition
to any other vote or consent of shareholders required by law or by the
Declaration of Trust of the Trust, the affirmative vote or consent of at least
66-2/3% of the votes entitled to be cast by the holders of the outstanding
Series E Preferred Shares voting as a single class with the holders of all other
classes or series of Voting Parity Shares entitled to vote on such matters,
given in person or by proxy, either in writing without a meeting or by vote at
any meeting called for the purpose, shall be necessary for effecting or
validating:

          (i) Any amendment, alteration or repeal of any of the provisions of,
     or the addition of any provision to, these Articles Supplementary, the
     Declaration of Trust or the By-Laws of the Trust that materially adversely
     affects the voting powers, rights or preferences of the holders of the
     Series E Preferred Shares; provided, however, that the amendment of or
     supplement to the provisions of the Declaration of Trust to authorize,
     create, increase or decrease the authorized amount of, or to issue Junior
     Shares, Series E Preferred Shares or any class of Parity Shares shall not
     be deemed to materially adversely affect the voting powers, rights or
     preferences of the holders of Series E Preferred Shares; or

          (ii) The authorization, creation of, increase in the authorized amount
     of, or issuance of shares of any class or series of Senior Shares or any
     security convertible into shares of any class or series of Senior Shares
     (whether or not such class or series of Senior Shares is currently
     authorized);

provided, however, that no such vote of the holders of Series E Preferred Shares
shall be required if, at or prior to the time when such amendment, alteration or
repeal is to take effect, or when the issuance of any such Senior Shares or
convertible or exchangeable security is to be made, as the case may be,
provision is made for the redemption of all outstanding Series E Preferred
Shares to the extent such redemption is authorized by Section 5 of this Article.

     For purposes of the foregoing provisions and all other voting rights under
these Articles Supplementary, each Series E Preferred Share shall have one (1)
vote per share, except that when any other class or series of preferred shares
of the Trust shall have the right to vote with the Series E Preferred Shares as
a single class on any matter, then the Series E Preferred Shares and such other
class or series shall have with respect to such matters one quarter of one vote
per $25.00 of stated liquidation preference. Except as otherwise required by
applicable law or as set forth herein or in the Declaration of Trust, the Series
E Preferred Shares shall not have any relative, participating, optional or other
special voting rights and powers other than as set forth herein, and the consent
of the holders thereof shall not be required for the taking of any action by the
Trust.


                                       18



(c) In no event shall the Series A Preferred Shares be treated as Parity Shares
for the purposes of this Section 8, and the voting rights of the Series A
Preferred Shares as fixed by the Articles Supplementary establishing such series
remain in full force and effect.

     9.   RECORD HOLDERS.

     The Trust and the Transfer Agent may deem and treat the record holder of
any Series E Preferred Share as the true and lawful owner thereof for all
purposes, and neither the Trust nor the Transfer Agent shall be affected by any
notice to the contrary.

     10.  RESTRICTIONS ON OWNERSHIP AND TRANSFER; REMEDIES.

     Article VII of the Declaration of Trust sets forth certain ownership and
transfer restrictions relating to the Equity Shares, including the Series E
Preferred Shares. Article VII of the Declaration of Trust is hereby incorporated
by reference herein.

FOURTH: These Articles Supplementary have been duly adopted by all necessary
action on the part of the Trust.


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IN WITNESS WHEREOF, the Trust has caused these presents to be signed in its name
and on its behalf by its Chief Executive Officer and witnessed by its Assistant
Secretary on April 3, 2001.



                                              CORPORATE OFFICE PROPERTIES TRUST


WITNESS:

 /s/ John Gurley
- ----------------------------------
Name:  John Gurley                            By: /s/ Randall M. Griffin
Title: Vice President & General                  -------------------------------
        Counsel                                  Name:   Randall M. Griffin
                                                 Title:  President  & Chief
                                                          Operating Officer



THE UNDERSIGNED, President and Chief Operating Officer of CORPORATE OFFICE
PROPERTIES TRUST, who executed on behalf of the Trust the Articles Supplementary
of which this Certificate is made a part, hereby acknowledges in the name and on
behalf of said Trust the foregoing Articles Supplementary to be the official act
of said Trust and hereby certifies that the matters and facts set forth herein
with respect to the authorization and approval thereof are true in all material
respects under the penalties of perjury.


 /s/ Randall M. Griffin
- -------------------------------------
Name:  Randall M. Griffin
Title: President & Chief Operating Officer



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