Abstract: To solve the problems of low dependability of irrigation and less efficient operation of irrigation projects in pumping and storage irrigation systems, this paper presents an optimal operation model for a typical system in South Cnina. The model consists of a multi-dimension dynamic programming model, a simulation model, and some other optimization models, which can be used to provide optimal allocation ofirrigation water in time and space effectively. The case study has confirmed that the application of the model can increase dependabilites of irrigation and economic beaifits of the irrigation projects. The model provides a new way of increasing irrigation benifits for the similar systems.