Exhibit 12.1

Ameren Corporation

Computation of Ratio of Earnings to Fixed Charges

(Thousands of Dollars, Except Ratios)

	Three Months Ended March  31, 2010		Year Ended        December 31,        2009
Net income from continuing operations attributable to Ameren Corporation	$	102,297	$	612,313
Less- Net income attributable to noncontrolling interests		(1,412)		(2,007)
Add- Taxes based on income		74,519		332,128
Net income before income taxes and noncontrolling interests		178,228		946,448
Add- fixed charges:
Interest on short-term and long-term debt (a)		134,654		518,149
Estimated interest cost within rental expense		1,975		8,341
Amortization of net debt premium, discount, and expenses		3,635		16,183
Subsidiary preferred stock dividends		2,469		9,874
Adjust preferred stock dividends to pretax basis		1,756		5,271
Total fixed charges		144,489		557,818
Less: Adjustment of preferred stock dividends to pretax basis		1,756		5,271
Earnings available for fixed charges	$	320,961	$	1,498,995
Ratio of earnings to fixed charges		2.22		2.68

^(a) Includes interest expense related to uncertain tax provisions.