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,
	2009		2008		2009			2008
Net income	$	24,186	$	21,814	$	70,562		$	62,243
Interest expense		875		988		2,686			2,971

Earnings from operations available to cover fixed charges	$	25,061	$	22,802	$	73,248		$	65,214

Fixed charges ⁽¹⁾	$	875	$	988	$	2,686		$	2,971
Preferred stock dividends		11,156		12,756		6,285			38,269
Preferred partnership distributions		1,382		1,752		(3,951	)		5,256

Combined fixed charges and preferred distributions	$	13,413	$	15,496	$	5,020		$	46,496

Ratio of earnings from operations to fixed charges		28.6		23.1		27.3			22.0

Ratio of earnings from operations to combined fixed charges and preferred distributions		1.9		1.5		14.6			1.4


	For the Years Ended December 31,
	2008		2007		2006		2005		2004
Income from continuing operations	$	85,347	$	81,675	$	79,205	$	75,936	$	71,349
Interest expense		3,952		4,130		2,575		1,330		3,054

Earnings from continuing operations available to cover fixed charges	$	89,299	$	85,805	$	81,780	$	77,266	$	74,403

Fixed charges ⁽¹⁾	$	3,952	$	4,130	$	2,575	$	1,330	$	3,054
Preferred stock dividends		46,630		50,937		47,933		43,011		33,020
Preferred partnership distributions		7,007		6,854		11,155		10,651		20,245

Combined fixed charges and preferred distributions	$	57,589	$	61,921	$	61,663	$	54,992	$	56,319

Ratio of earnings from continuing operations to fixed charges		22.6		20.8		31.8		58.1		24.4

Ratio of earnings from continuing operations to combined fixed charges and preferred distributions		1.6		1.4		1.3		1.4		1.3


(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,
	2009		2008		2009			2008
FFO	$	31,476	$	32,009	$	130,371		$	93,988
Interest expense		875		988		2,686			2,971
Net income allocable to noncontrolling interests — preferred units		1,382		1,752		(3,951	)		5,256
Preferred stock dividends		11,156		12,756		6,285			38,269

FFO available to cover fixed charges	$	44,889	$	47,505	$	135,391		$	140,484

Fixed charges ⁽¹⁾	$	875	$	988	$	2,686		$	2,971
Preferred stock dividends ⁽²⁾		11,156		12,756		33,507			38,269
Preferred partnership distributions ⁽²⁾		1,382		1,752		4,466			5,256

Combined fixed charges and preferred distributions paid	$	13,413	$	15,496	$	40,659		$	46,496

Ratio of adjusted FFO to fixed charges		51.3		48.1		50.4			47.3

Ratio of adjusted FFO to combined fixed charges and preferred distributions paid		3.3		3.1		3.3			3.0


	For the Years Ended December 31,
	2008		2007		2006		2005		2004
FFO	$	131,558	$	122,405	$	106,235	$	102,608	$	97,340
Interest expense		3,952		4,130		2,575		1,330		3,054
Net income allocable to noncontrolling interests — preferred units		7,007		6,854		11,155		10,651		20,245
Preferred stock dividends		46,630		50,937		47,933		43,011		33,020

FFO available to cover fixed charges	$	189,147	$	184,326	$	167,898	$	157,600	$	153,659

Fixed charges ⁽¹⁾	$	3,952	$	4,130	$	2,575	$	1,330	$	3,054
Preferred stock dividends ⁽²⁾		50,858		50,937		44,553		43,011		31,154
Preferred partnership distributions ⁽²⁾		7,007		6,854		9,789		10,350		17,106

Combined fixed charges and preferred distributions paid	$	61,817	$	61,921	$	56,917	$	54,691	$	51,314

Ratio of adjusted FFO to fixed charges		47.9		44.6		65.2		118.5		50.3

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


(1)		Fixed charges include interest expense.

(2)		Excludes Emerging Issues Task Force Topic D-42 distributions.