Exhibit 12

PS BUSINESS PARKS, INC.

EXHIBIT 12
STATEMENT RE: COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
(Unaudited, in thousands, except ratio data)


	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
	2010		2009		2010		2009
Income from continuing operations	$	23,559	$	23,313	$	72,703	$	66,821
Interest expense		875		875		2,586		2,686

Earnings from continuing operations available to cover fixed charges	$	24,434	$	24,188	$	75,289	$	69,507

Fixed charges ⁽¹⁾	$	875	$	875	$	2,586	$	2,686
Preferred stock dividends		10,080		11,156		33,958		6,285
Preferred partnership distributions		984		1,382		4,118		(3,951	)

Combined fixed charges and preferred distributions	$	11,939	$	13,413	$	40,662	$	5,020

Ratio of earnings from continuing operations to fixed charges		27.9		27.6		29.1		25.9

Ratio of earnings from continuing operations to combined fixed charges and preferred distributions		2.0		1.8		1.9		13.8


	For the Years Ended December 31,
	2009			2008		2007		2006		2005
Income from continuing operations	$	92,021		$	84,750	$	81,112	$	78,504	$	75,617
Interest expense		3,552			3,952		4,130		2,575		1,330

Earnings from continuing operations available to cover fixed charges	$	95,573		$	88,702	$	85,242	$	81,079	$	76,947

Fixed charges ⁽¹⁾	$	3,552		$	3,952	$	4,130	$	2,575	$	1,330
Preferred stock dividends		17,440			46,630		50,937		47,933		43,011
Preferred partnership distributions		(2,569	)		7,007		6,854		11,155		10,651

Combined fixed charges and preferred distributions	$	18,423		$	57,589	$	61,921	$	61,663	$	54,992

Ratio of earnings from continuing operations to fixed charges		26.9			22.4		20.6		31.5		57.9

Ratio of earnings from continuing operations to combined fixed charges and preferred distributions		5.2			1.5		1.4		1.3		1.4


⁽¹⁾		Fixed charges include interest expense.

PS BUSINESS PARKS, INC.
EXHIBIT 12
STATEMENT RE: COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
(Unaudited, in thousands, except ratio data)

Supplemental Disclosure of Ratio of Funds from Operations (“FFO”) to Fixed Charges:


	For the Three Months				For the Nine Months
	Ended September 30,				Ended September 30,
	2010		2009		2010		2009
FFO	$	33,695	$	31,476	$	92,717	$	130,371
Interest expense		875		875		2,586		2,686
Net income allocable to noncontrolling interests — preferred units		984		1,382		4,118		(3,951	)
Preferred stock dividends		10,080		11,156		33,958		6,285

FFO available to cover fixed charges	$	45,634	$	44,889	$	133,379	$	135,391

Fixed charges ⁽¹⁾	$	875	$	875	$	2,586	$	2,686
Preferred stock dividends ⁽²⁾		10,080		11,156		32,104		33,507
Preferred partnership distributions ⁽²⁾		984		1,382		3,536		4,466

Combined fixed charges and preferred distributions paid	$	11,939	$	13,413	$	38,226	$	40,659

Ratio of adjusted FFO to fixed charges		52.2		51.3		51.6		50.4

Ratio of adjusted FFO to combined fixed charges and preferred distributions paid		3.8		3.3		3.5		3.3


	For the Years Ended December 31,
	2009			2008		2007		2006		2005
FFO	$	163,074		$	131,558	$	122,405	$	106,235	$	102,608
Interest expense		3,552			3,952		4,130		2,575		1,330
Net income allocable to noncontrolling interests — preferred units		(2,569	)		7,007		6,854		11,155		10,651
Preferred stock dividends		17,440			46,630		50,937		47,933		43,011

FFO available to cover fixed charges	$	181,497		$	189,147	$	184,326	$	167,898	$	157,600

Fixed charges ⁽¹⁾	$	3,552		$	3,952	$	4,130	$	2,575	$	1,330
Preferred stock dividends ⁽²⁾		44,662			50,858		50,937		44,553		43,011
Preferred partnership distributions ⁽²⁾		5,848			7,007		6,854		9,789		10,350

Combined fixed charges and preferred distributions paid	$	54,062		$	61,817	$	61,921	$	56,917	$	54,691

Ratio of adjusted FFO to fixed charges		51.1			47.9		44.6		65.2		118.5

Ratio of adjusted FFO to combined fixed charges and preferred distributions paid		3.4			3.1		3.0		2.9		2.9


⁽¹⁾		Fixed charges include interest expense.

⁽²⁾		Excludes the issuance costs related to the redemption/repurchase of preferred equity and the gain on the repurchase of preferred equity.