Abstract: Rainfall and flood forecasting are crucial for reservoir flood control and comprehensive benefits operation. Longrange precipitation prediction and flood probability forecasting not only can extend prediction leading times,but also can consider uncertainty and increase accuracy. Reservoir flood probability forecasting and dynamic control of reservoir water level can effectively increase floodwater utilization rate without increasing flood prevention risks. It is suggested to further study rainfall flood probability forecasting and reservoir flood control limted water level for raising scientific management level.