X0306 4 2015-09-08 0 0000866368 PS BUSINESS PARKS INC/CA PSB 0001227459 HAWTHORNE MARIA R C/O PS BUSINESS PARKS, INC 701 WESTERN AVENUE GLENDALE CA 91201 0 1 0 0 President Common Stock 2015-09-08 4 M 0 16550 50.63 A 34411 D Common Stock 2015-09-08 4 S 0 16550 74.0194 D 17861 D Common Stock 2015-09-08 4 S 0 7000 74.0161 D 10861 D Common Stock 10001.956 I By 401(k) Plan Stock Option (right to buy) 50.63 2015-09-08 4 M 0 16550 0 D 2011-03-15 2020-03-15 Common Stock 16550 0 D Includes 7,200 restricted stock units. Represents weighted average price. These shares were sold at prices ranging between $73.8650 and $74.19. Full information regarding the number of shares sold at each separate price will be provided by the reporting person upon request to the staff of the Securities and Exchange Commission, the issuer or a security holder of the issuer. Represents weighted average price. These shares were sold at prices ranging between $73.87 and $74.18. Full information regarding the number of shares sold at each separate price will be provided by the reporting person upon request to the staff of the Securities and Exchange Commission, the issuer or a security holder of the issuer. 401(k) plan units that represent interest in common stock; based on plan information as of September 8, 2015. There is not a one to one correlation between units and shares. Stock option granted pursuant to the 2003 Stock Option and Incentive Plan. This option was previously reported as an option for 40,000 shares of common stock at an exercise price of $52.35, but was adjusted to reflect the special dividend declared by PSB on December 15, 2014. /s/ Lily Y. Hughes, Attorney-in-Fact 2015-09-10