Abstract:The main hydrology factors in one river includes precipitation, runoff and sediment discharge. These three hydrology factors are impacted largely by regional land use/ land cover change. The Yanhe River Basin with the area of 7725km2 and in middle of the Loess Plateau, is one of the hot-spots for regional afforestation and soil water conservation in China. So studying on the temporal change of the main hydrology factors in the Yanhe River Basin is very essential for providing the basic information and supporting the decision of local government. We collected the precipitation data and worked out the regional tendency from the 6 wide-spreaded rain gauge stations from the middle of 20th century to 21st century. We also got the runoff and sedimentation discharge data from 2 hydrology stations in the same period. It's founded: (1) The monthly distribution of each of those three main hydrology factors tended to be uniform, and the annual change was prone to be tempered. (2) Compared to the average in 1960s, the annual precipitation in the 1970s, 1980s and 1990s in the basin, has respectively reduced by 10.5%, 11.7% and 14.0%. (3) The annual water yield in the basin has separately reduced by sediment discharge, reduced by 14.1%, 13.1% and 21.4%. (4) The annual sediment discharge reduced by 21.1%, 46.2% and 41.7%.