Exhibit 12.1

Ameren Corporation

Computation of Ratio of Earnings to Fixed Charges

(Thousands of Dollars, Except Ratios)

	Year Ended December 31,
	2005			2006			2007			2008			2009
Net income from continuing operations attributable to Ameren Corporation	$	605,725		$	546,738		$	617,804		$	605,189		$	612,313
Less- Change in accounting standard		(22,135	)		—			—			—			—
Less- Net income attributable to noncontrolling interests		(3,231	)		(27,135	)		(27,266	)		(28,422	)		(2,007	)
Add- Taxes based on income		356,016			283,825			330,141			326,736			332,128
Net income before income taxes, change in accounting standard, and noncontrolling interests		987,107			857,698			975,211			960,347			946,448
Add- fixed charges:
Interest on short-term and long-term debt		297,822			345,410			421,406	(1)		440,507	(1)		518,149	(1)
Estimated interest cost within rental expense		4,208			4,081			5,020			6,510			8,341
Amortization of net debt premium, discount, and expenses		14,687			15,341			18,638			19,716			16,183
Subsidiary preferred stock dividends		12,745			10,936			10,871			10,357			9,874
Adjust preferred stock dividends to pretax basis		7,227			5,565			5,709			5,497			5,271
Total fixed charges		336,689			381,333			461,644			482,587			557,818
Less: Adjustment of preferred stock dividends to pretax basis		7,227			5,565			5,709			5,497			5,271
Earnings available for fixed charges	$	1,316,569		$	1,233,466		$	1,431,146		$	1,437,437		$	1,498,995
Ratio of earnings to fixed charges		3.91			3.23			3.10			2.97			2.68

⁽¹⁾ Includes FIN 48 interest expense