Exhibit 12

PS BUSINESS PARKS, INC.

STATEMENT RE: COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES

(in thousands, except ratio data)

	2010		2009			2008		2007		2006
Income from continuing operations	$	96,835	$	92,021		$	84,750	$	81,112	$	78,504
Interest expense		3,534		3,552			3,952		4,130		2,575
Earnings from continuing operations available to cover fixed charges	$	100,369	$	95,573		$	88,702	$	85,242	$	81,079
Fixed charges(1)	$	3,534	$	3,552		$	3,952	$	4,130	$	2,575
Preferred stock dividends		46,214		17,440			46,630		50,937		47,933
Preferred partnership distributions		5,103		(2,569	)		7,007		6,854		11,155
Combined fixed charges and preferred distributions	$	54,851	$	18,423		$	57,589	$	61,921	$	61,663
Ratio of earnings from continuing operations to fixed charges		28.4		26.9			22.4		20.6		31.5
Ratio of earnings from continuing operations to combined fixed charges and preferred distributions		1.8		5.2			1.5		1.4		1.3

Supplemental disclosure of Ratio of Funds from Operations (“FFO”) to fixed charges:

	2010		2009			2008		2007		2006
FFO	$	124,420	$	163,074		$	131,558	$	122,405	$	106,235
Interest expense		3,534		3,552			3,952		4,130		2,575
Net income allocable to noncontrolling interests — preferred units		5,103		(2,569	)		7,007		6,854		11,155
Preferred stock dividends		46,214		17,440			46,630		50,937		47,933
FFO available to cover fixed charges	$	179,271	$	181,497		$	189,147	$	184,326	$	167,898
Fixed charges(1)	$	3,534	$	3,552		$	3,952	$	4,130	$	2,575
Preferred stock dividends(2)		42,730		44,662			50,858		50,937		44,553
Preferred partnership distributions(2)		4,521		5,848			7,007		6,854		9,789
Combined fixed charges and preferred distributions paid	$	50,785	$	54,062		$	61,817	$	61,921	$	56,917
Ratio of adjusted FFO to fixed charges		50.7		51.1			47.9		44.6		65.2
Ratio of adjusted FFO to combined fixed charges and preferred distributions paid		3.5		3.4			3.1		3.0		2.9

(1)	Fixed charges include interest expense.
(2)	Excludes the non-cash distributions related to the redemption/repurchase of preferred equity and the gain on the repurchase of preferred equity.