Exhibit 12

EXHIBIT 12

PS BUSINESS PARKS, INC.

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


	For the Three Months
	Ended March 31,
	2010		2009
Income from continuing operations	$	22,654	$	21,532
Interest expense		855		930

Earnings from continuing operations available to cover fixed charges	$	23,509	$	22,462

Fixed charges ⁽¹⁾	$	855	$	930
Preferred stock dividends		11,155		(16,026	)
Preferred partnership distributions		1,382		(6,714	)

Combined fixed charges and preferred distributions	$	13,392	$	(21,810	)

Ratio of earnings from continuing operations to fixed charges		27.5		24.2

Ratio of earnings from continuing operations to combined fixed charges and preferred distributions		1.8		(2	)


	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.

⁽²⁾		Not meaningful as combined fixed charges and preferred stock dividends are negative.

EXHIBIT 12

PS BUSINESS PARKS, INC.

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
	Ended March 31,
	2010		2009
FFO	$	28,341	$	67,182
Interest expense		855		930
Net income allocable to noncontrolling interests — preferred units		1,382		(6,714	)
Preferred stock dividends		11,155		(16,026	)

FFO available to cover fixed charges	$	41,733	$	45,372

Fixed charges ⁽¹⁾	$	855	$	930
Preferred stock dividends ⁽²⁾		11,155		11,196
Preferred partnership distributions ⁽²⁾		1,382		1,703

Combined fixed charges and preferred distributions paid	$	13,392	$	13,829

Ratio of adjusted FFO to fixed charges		48.8		48.8

Ratio of adjusted FFO to combined fixed charges and preferred distributions paid		3.1		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 effect of redemption/repurchase of preferred equity.