Based on the characteristics of the Yangtze River floods and the principles of fuzzy sets theory, a fuzzy optimal model has been established for the flood system of the upper and middle reaches of this river. The system is divided into three subsystems with specific flood control objectives. The Three-Gorges Reservoir plays an important role in the system. A method for producing flood operation alternatives of the Three-Gorges Reservoir is presented. Finally, the model is validated with three typical historical floods. The results show that the model is effective and flexible.