Soil temperature is an important soil physical property. Seasonal and regional variations of soil temperature affect growth, propagation and distribution of soil organisms, which are closely related to agriculture and eco-environment. Based on the data of mean monthly soil temperature and air temperature and precipitation in China from 1971 to 2000, seasonal and regional variations of soil temperature in China and impacts of air temperature and precipitation on soil temperature were analyzed. Results indicate that seasonal variation of soil temperature in China was distinct. It was the most distinct from spring to summer, when the 20℃ contour line jumped up beyond 25℃ in latitude from south to north, and the mildest from winter to spring. The seasonal variation differed significantly from region to region. The relationships of soil temperature with air temperature and precipitation also varied with the region. In the temperate zone and the Qinghai-ibet Plateau, soil temperature was mainly affected by air temperature, while in the tropical and subtropical zones, both air temperature and precipitation contributed to the seasonal variation of soil temperature.