SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

MATHER ROBIN E

(Last)

(First)

(Middle)

701 WESTERN AVENUE

(Street)

GLENDALE

91201-2349

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
05/04/2004

3. Issuer Name and Ticker or Trading Symbol
PS BUSINESS PARKS INC/CA [ PSB ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Vice President

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	5,000⁽¹⁾	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option⁽²⁾	03/15/2005	03/15/2014	Common Stock	2,000	$44.2	D
Stock Option⁽²⁾	03/15/2006	03/15/2014	Common Stock	2,000	$44.2	D
Stock Option⁽²⁾	03/15/2007	03/15/2014	Common Stock	2,000	$44.2	D
Stock Option⁽²⁾	03/15/2008	03/15/2014	Common Stock	2,000	$44.2	D
Stock Option⁽²⁾	03/15/2009	03/15/2014	Common Stock	2,000	$44.2	D
Stock Option⁽³⁾	01/10/2004	01/10/2013	Common Stock	1,000	$31.66	D
Stock Option⁽³⁾	01/10/2005	01/10/2013	Common Stock	1,000	$31.66	D
Stock Option⁽³⁾	01/10/2006	01/10/2013	Common Stock	1,000	$31.66	D
Stock Option⁽³⁾	01/10/2007	01/10/2013	Common Stock	1,000	$31.66	D
Stock Option⁽³⁾	01/10/2008	01/10/2013	Common Stock	1,000	$31.66	D
Stock Option⁽³⁾	07/03/2002	07/03/2011	Common Stock	833	$28.38	D
Stock Option⁽³⁾	07/03/2003	07/03/2011	Common Stock	833	$28.38	D
Stock Option⁽³⁾	07/03/2004	07/03/2011	Common Stock	834	$28.38	D

Explanation of Responses:

1. Consists of 5,000 restricted stock units which vest as follows: 450 on 02/19/2005; 450 on 02/19/2006; 600 on 02/19/2007; 300 on each of 01/10/2005, 01/10/2006, 01/10/2007, 01/10/2008 and 01/10/2009; and 400 on each of 3/15/2006, 03/15/2007, 3/15/2008, 03/15/2009 and 03/15/2007.

2. Stock options granted pursuant to the 2003 Stock Option and Incentive Plan.

3. Stock options granted pursuant to the 1997 Stock Option and Incentive Plan.

	/s/ David Goldberg, Attorney in Fact	05/05/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.