Exhibit 12.1

Ameren Corporation

Computation of Ratio of Earnings to Fixed Charges

(Thousands of Dollars, Except Ratios)

	Nine Months Ended September 30, 2010 (a)		Year Ended December 31, 2009
Net income from continuing operations attributable to Ameren Corporation	$	87,321	$	612,313
Less- Net income attributable to noncontrolling interest		(3,412)		(2,007)
Add- Taxes based on income		294,846		332,128
Net income before income taxes and noncontrolling interest		385,579		946,448
Add- fixed charges:
Interest on short-term and long-term debt (b)		386,021		518,149
Estimated interest cost within rental expense		6,401		8,341
Amortization of net debt premium, discount, and expenses		10,840		16,183
Subsidiary preferred stock dividends		6,740		9,874
Adjust preferred stock dividends to pretax basis		3,869		5,271
Total fixed charges		413,871		557,818
Less: Adjustment of preferred stock dividends to pretax basis		3,869		5,271
Earnings available for fixed charges	$	795,581	$	1,498,995
Ratio of earnings to fixed charges		1.92		2.68

^(a) In the third quarter of 2010, Ameren Corporation recorded a goodwill and other impairment charge of $589 million. See Note 15—Goodwill and Other Asset Impairments of this Form 10 Q for additional information.

^(b) Includes interest expense related to uncertain tax positions