**Exhibit      12.1**

| **Ameren                      Corporation****Computation                      of Ratio of Earnings to Fixed Charges****(Thousands                      of Dollars, Except Ratios)** |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                                |   |   |   |   |
|                                                                                                                                                                                | **Six                      Months** |   | **Year** |   |
|                                                                                                                                                                                | **Ended** |   | **Ended** |   |
|                                                                                                                                                                                | **June                      30,** |   | **December                      31,** |   |
|                                                                                                                                                                                |   | **2006** |   |   | **2005** |   |
| Net                      income from continuing operations                                                                                                                          | $ | 192,531 |   | $ | 605,725 |   |
| Less-                      Change in accounting principle                                                                                                                           |   | - |   |   | (22,135 | ) |
| Less-                      Minority interest                                                                                                                                        |   | (12,175 | ) |   | (3,231 | ) |
| Add-                      Taxes based on income                                                                                                                                     |   | 112,039 |   |   | 356,016 |   |
| Net                      income before income taxes, change in accounting                      principle, and minority interest                                                     |   | 316,745 |   |   | 987,107 |   |
|                                                                                                                                                                                |   |   |   |   |   |   |
| Add-                      fixed charges:                                                                                                                                            |   |   |   |   |   |   |
| Interest                      on long term debt                                                                                                                                     |   | 153,681 |   |   | 297,822 |   |
| Estimated                      interest cost within rental expense                                                                                                                  |   | 2,054 |   |   | 4,208 |   |
| Amortization                      of net debt premium, discount,and                      expenses                                                                                   |   | 7,122 |   |   | 14,687 |   |
| Subsidiary                      preferred stock dividends                                                                                                                           |   | 5,339 |   |   | 12,745 |   |
| Adjust                      preferred stock dividends to pre-taxbasis                                                                                                               |   | 3,023 |   |   | 7,227 |   |
| Total                      fixed charges                                                                                                                                            |   | 171,219 |   |   | 336,689 |   |
| Less:                      Adjustment of preferred stock dividends to pre-tax                      basis                                                                            |   | 3,023 |   |   | 7,227 |   |
|                                                                                                                                                                                |   |   |   |   |   |   |
| Earnings                      available for fixed charges                                                                                                                           |   | 484,941 |   |   | 1,316,569 |   |
|                                                                                                                                                                                |   |   |   |   |   |   |
| Ratio                      of earnings to fixed charges                                                                                                                             |   | 2.83 |   |   | 3.91 |   |
|                                                                                                                                                                                |   |   |   |   |   |   |