Abstract: Irrigation problems of winter wheat in arid regions are studied in this paper. By analyzing the crop model and the crop moisture response function, with the aim of maximum yields, this paper presents a two dimensional dynamic programming model so as to optimize non-sufficient irrigation schedules. A related calculation method of dynamic programming successive approximations (DPSA) has been given. The model has been used to solve practical problems in Xiaobudong irrgation district, Linyi city, Shandong Province. The optimum irrigation schedules, the processes of drainage and the related yields for three typical years with different supply water are obtained. The example shows that the model and the method are reasonable.