Abstract: The atmospheric moisture content and water vapour transport flux over the Sanxi Province has been computed,the results show that the seasonal variation of moisture content is more obvious than those of other regions in China and some cyclical processes seem to exist in the secular variation;the annual net-inflow amount of atmospheric moisture in 1990 is about 5350×10⁸ m³ with coming mainly from the west-south boundary and escaping mainly from the east boundary. Based on the computation of atmospheric moisture content,water vapour transport and other hydrologic balance components,a hydrological cycle model of the Sanxi Province has been developed. The model shows some characteristics of hydrological cycle in the Sanxi Province:(1)The use rate of atmospheric moisture is about 30%which is lower than the average use rate of the whole country;(2) The contribution of precipitation formed by local evaporation to the total precipitation is about 15%,showing the hydrologic re-cycle is active,especially more active than those of the area south to Yangtze River Basin;(3) The influence of groundwater minig on hydrologic cycle components has became visible,which may feat to some harmfuleffects for the environment.