X0303 4 2011-03-28 0 0000866368 PS BUSINESS PARKS INC/CA PSB 0001273398 STOKX EDWARD A C/O PS BUSINESS PARKS, INC. 701 WESTERN AVENUE GLENDALE CA 91201 0 1 0 0 EVP & CHIEF FINANCIAL OFFICER Common Stock 2011-03-28 4 F 0 221 57.10 D 6679 D Stock Option (right to buy) 52.35 2011-03-15 2020-03-15 Common Stock 35000 35000 D Includes 584 restricted stock units. Stock Options granted pursuant to the 2003 Stock Option and Incentive Plan. /s/ Edward A. Stokx 2011-03-30