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                                                         Exhibit 10.1

                                   Agreement
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     This Agreement is entered into as of this 15th day of February, 2001,
between Parametric Technology Corporation, a Massachusetts corporation (the
"Company"), and Trenton H. Brown ("Brown").

     WHEREAS, Brown is the Executive Vice President, European Sales; and

     WHEREAS, to provide incentive for Brown to maintain employment with the
Company, the Company desires to make the following arrangements with Brown
concerning his termination of employment.

     NOW, THEREFORE, the Company and Brown hereby agree as follows:

     1. Termination Notice. The Company agrees that it may not terminate
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the employment of Brown unless (i) such termination is for Cause (as
defined below) or (ii) the Company has delivered to Brown a written notice
of such termination (the "Termination Notice") at least six months in
advance of the termination date. The duties of Brown during the period from
the date of delivery of a Termination Notice until the termination of his
employment shall be as determined by the Board of Directors or the Chief
Executive Officer.

     2. Salary. During the period from the date of delivery of the
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Termination Notice (the "Notice Date") until the earlier of (i) the date
six months after the Notice Date or (ii) the date Brown commences
employment with another company or organization, the Company shall pay to
Brown a salary that is equal, on an annualized basis, to the highest annual
salary (excluding any bonuses) in effect with respect to Brown during the
six-month period immediately preceding the Termination Notice.

     3. Stock Options. Effective upon a Change in Control (as defined
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below) of the Company, all stock options granted to Brown and then
outstanding under any Stock Option Plan (as defined below) of the Company
shall become exercisable in full, notwithstanding any vesting schedule or
other provisions to the contrary in the agreements evidencing such options;
and the Company and Brown hereby agree that such option agreements are
hereby and will be deemed amended to give effect to this provision.

     4. Definitions.
        -----------

     (a) A termination by the Company of Brown's employment for "Cause" shall
mean termination (i) for Brown's willful and continued failure to substantially
perform his duties to the Company (other than any such

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failure resulting from Brown's incapacity due to physical or mental
illness), provided that (a) the Company has delivered a written demand for
substantial performance to Brown specifically identifying the manner in
which the Company believes that Brown has not substantially performed his
duties, and (b) Brown has not cured such failure within 30 days after such
demand, (ii) for willful conduct by Brown which is demonstrably and
materially injurious to the Company, or (iii) for Brown's willful violation
of any material provision of any confidentiality, nondisclosure, assignment
of invention, noncompetition or similar agreement entered into by Brown in
connection with his employment by the Company. For purposes of this
paragraph, no act or failure to act on Brown's part shall be deemed
"willful" unless done or omitted to be done by Brown not in good faith and
without reasonable belief that his action or omission was in the best
interests of the Company.

     (b) A "Change in Control" of the Company shall mean the occurrence of
any of the following events: (i) any "person", as such term is used in
Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended
(the "Exchange Act") (other than the Company, any trustee or other
fiduciary holding securities under an employee benefit plan of the Company,
or any corporation owned directly or indirectly by the stockholders of the
Company in substantially the same proportion as their ownership of stock in
the Company) is or becomes the "beneficial owner" (as defined in Rule 13d-3
under the Exchange Act), directly or indirectly, of securities of the
Company representing 50% or more of the combined voting power of the
Company's then outstanding securities (other than as a result of
acquisitions of such securities from the Company); (ii) individuals who, as
of the date hereof, constitute the Board of Directors of the Company (the
"Incumbent Board") cease for any reason to constitute at least a majority
of the Board, provided that any person becoming a director subsequent to
the date hereof whose election, or nomination for election by the Company's
stockholders, was approved by a vote of at least a majority of the
directors then comprising the Incumbent Board (other than an election or
nomination of an individual whose initial assumption of office is in
connection with an actual or threatened election contest relating to the
election of the directors of the Company) shall be, for purposes of this
Agreement, considered to be a member of the Incumbent Board; (iii) the
stockholders of the Company approve a merger or consolidation of the
Company with any other corporation, other than (A) a merger or
consolidation which would result in the voting securities of the Company
outstanding immediately prior thereto continuing to represent (either by
remaining outstanding or by being converted into voting securities of the
surviving entity) more than

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50% of the combined voting power of the voting securities of the Company or
such surviving entity outstanding immediately after such merger or
consolidation or (B) a merger or consolidation effected to implement a
recapitalization of the Company (or similar transaction) in which no
"person" (as defined above) acquires more than 20% of the combined voting
power of the Company's then outstanding securities; or (iv) the
stockholders of the Company approve a plan of complete liquidation of the
Company.

(c) A "Stock Option Plan" of the Company shall mean any stock option or
equity compensation plan of the Company in effect at any time, including
without limitation the 1987 Incentive Stock Option Plan, the 1997 Incentive
Stock Option Plan, the 1997 Non-statutory Stock Option Plan and the 2000
Equity Incentive Plan.

     5. Term. This Agreement shall continue in effect until February 28,
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2003, unless extended by the mutual written consent of the Company and
Brown.

     6. Successors.
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     (a) This Agreement is personal to Brown and without the prior written
consent of the Company shall not be assignable by Brown otherwise than by will
or the laws of descent and distribution.

     (b) This Agreement shall inure to the benefit of and be binding upon the
Company and its successors and assigns.

     (c) The Company will require any successor (whether direct or
indirect, by purchase, merger, consolidation or otherwise) to all or
substantially all of the business and/or assets of the Company to assume
expressly and agree to perform this Agreement in the same manner and to the
same extent that the Company would be required to perform it if no such
succession had taken place. As used in this Agreement, "Company" shall mean
the Company as defined above and any successor to its business and/or
assets as aforesaid which assumes and agrees to perform this Agreement.

     7. Miscellaneous.
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     (a) This Agreement shall be governed by and construed in accordance with
the laws of the Commonwealth of Massachusetts, without reference to principles
of conflict of laws.

     (b) This Agreement may not be amended or modified otherwise than by a
written agreement executed by the parties hereto or their respective successors
and legal representatives.

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     (c) All notices and other communications hereunder shall be in writing
and shall be delivered by hand delivery, by a reputable overnight courier
service, or by registered or certified mail, return receipt requested,
postage prepaid, in each case addressed as follows:

If to the Company:
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Parametric Technology Corporation
140 Kendrick Street
Needham, MA 02494
Attention: Senior Vice President - General Counsel

If to Brown:
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Trenton H. Brown
145 Oakwood Court
Abbotsbury Road
Kensington, London W14 8JS

or to such other address as either party shall have furnished to the other
in writing in accordance herewith. Any notice or communication shall be
deemed to be delivered upon the date of hand delivery, one day following
delivery to such overnight courier service, or three days following mailing
by registered or certified mail.

EXECUTED as of the date first written above.

                            PARAMETRIC TECHNOLOGY CORPORATION

                            By: /s/ C. Richard Harrison
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                                C. Richard Harrison
                                Chief Executive Officer and President

                                /s/ Trenton H. Brown
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                                Trenton H. Brown

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