Abstract: Sedimentation is a crucial problem which influences the comprehensive benefits and long term operation of Three Gorges Project. In recent years, sediment from the upstream to the Three Gorges Reservoir has decreased remarkably, which indicates that the sedimentation condition is better than that of anticipation. On the basis of measured hydrological data, the variations of incoming flow and sediment and deposition in Three Gorges Reservoir area are analyzed. It's put forward that, in view of the inflow in October, reservoir impoundment in advance is necessary. Furthermore, the feasibility of the reservoir's optimum operation is discussed based on relative results and medium and small flood control practice in the flood season of 2010. It is presented that the water level could raise to 150m in flood season during the impoundment, and the medium and small flood could be regulated according to reality, which can accumulate experience for future operation.

Key words: Three Gorges Project, reservoir, sediment, operation