Abstract: In order to know the soil moisture and maize growth relationship, improve the utilization rate of soil water, to coordinate the deployment of water resources and provide a theoretical basis for disaster prevention and reduction, 0-50 cm growing season soil moisture and yield of maize using observation data of 1994-2010 weather for agriculture in Xin House District Stations, Xinzhou City, Shanxi Province in spring maize, the author analyzed the effects of maize growth variation in soil water season and on maize yield. The results showed that: the spring maize growing season soil moisture variability oscillation obviously, was change, and the annual precipitation was related significantly; 3 phase change of soil moisture in a year was divided into water consuming stage, water supply and water stable period; the vertical variation of soil moisture significantly, in the 20-30 cm layer maximum moisture content, 0-20 cm for multiple layer, 20-50 cm as the buffer layer, soil moisture variation of rainy season than dry season complex; maize jointing stage, milk stage water storage in soil and climate yield were positively correlated, tasseling stage was the critical period of water requirement, the 0-50 cm soil water storage increased by 10 mm, increased production of 200-250 kg/hm²。.