The Yellow River water is most important resources of agricultural and industrial production in north and northwest China. It is very important to distribute the resources rationally in time, space and quantity so as to be mutually complementary with the precipitation according to the distribution characteristics of the precipition and the regularity of agricultural water requirment. In this paper, the author made use of the empirical orthogonal function (EOF) method to analyse some distribution characteristics of the precipitation of different year-types and of growth periods of main crops. Furthermore, some suggestions were made about how to use the water resources of the Yellow River rationaly.