Abstract: As the water source conservation area of Miyun Reservoir,Zhangcheng Area in the upper reaches of Miyun Reservoir bears the important task of providing drinking water to Beijing.The study of water supply service in Zhangcheng Water Source Conservation Area is of great significance to the high-quality development and ensuring the water ecological security of the capital. Based on the remote sensing the land use change in Zhangcheng Water Conservation Area were interpreted and analyzed from 2000 to 2019. Based on the InVEST water yield model the spatial distribution and change of water yield in the study area from 2000 to 2019 were quantitatively evaluated,and the relationship between water yield change and land use evolution was discussed by using scenario analysis.The results show that :（1） From 2000 to2019,the overall land use in the study area was characterized by the decrease in plow land,and the increase in forest land,grassland and construction land.（2）The total water yield of the study area in 2000,2010 and 2019 was 2.61,3.46 and 2.71 million m3.The water yield in different periods showed spatial heterogeneity,which changed gradually from high in the west and low in the east into high in the east and low in the west.（3） The average depth of water yield of different land use types in the study area from large to small is:construction land,bare land,water area,plow land,forest land and grass land. When the evapotranspiration coefficient remains unchanged,the change of land use from land type with low water yield capacity to land type with high water yield capacity will lead to an increase in regional water yields,and vice versa.