Abstract:Mihuaishun Water Source Conservation Area is located at the junction of Miyun, Huairou and Shunyi districts, which possess Beijing No 8 Water Plant and Huairou Emergency Water Source. Since the South-North Water Transfer Project in Beijing at the end of 2014, partial surplus water has started to replenish underground water of Mihuaishun through the Chaobai River Channel. In order to protect drinking water sources and find out potential risks of historical non-point source pollution, the ArcGIS and transfer matrix model were used to investigate the spatial and temporal evolution of land use. The research results show that: 1) The intensity of land use change from 2012 to 2015 is 5.24 times than that from 2015 to 2018, and. 2) The rates of forestland, water area, wetland and cultivated land are greatly changed, which are 92.15%, 67.46% and 46.6% respectively. 3) The forestland, water area, wetland, grassland and unused land show a net roll-in trend, while the cultivated and construction areas show a net roll-out trend after 2015.4) 68.23km2 cultivated land is conversed into forestland, which is considered as the most active land attribute change. 5) The characteristics of land use change are closely related to policy driving forces. The research indicates that the cultivated land and unused area are decreasing, while the forestland, water area, wetland and grassland are increasing, and the construction land is first increased but then decreased. And the evolution trend of land use is conductive to the development of safe drinking water sources. It is wished that this thesis could provide scientific basis for prevention and control of non-point source pollution in water conservation areas , and lay a foundation for further studies on the influence of agricultural non-point sources on soil and groundwater environment in the conservation area.