The Huangfuchuan River Basin was taken as the study area to explore the quantitative relationship between the sediment discharge reduction and rainfall variation,as well as soil and water conservation measures in tributaries of the middle Yellow River.Based on the data of daily precipitation at the Jungar meteorological station and annual runoff and sediment discharge at the Huangfu hydrological station from 1960 to 2015,the precipitation parameters affecting the annual runoff and sediment discharge in the Huangfuchuan River Basin were analyzed.Three typical periods of sediment discharge variation were Per1(1960-1986),Per2(1987-1999),Per3(2000-2015) using the double mass curve analysis and the Pettitt test,and the contribution rate of rainfall change,vegetation restoration and soil and water conservation measures to the variation in sediment discharge in different periods is calculated.The results showed that:(1) During the period of 1960-2015,the daily rainfall intensity exceeded 25mm/d reduced in Huangfuchuan River Basin,and the runoff and sediment discharge also displayed a decreasing trend (with the parameter Z＜0 and P<0.01 using the M—K trend tests);(2) Due to the change in the underlying surface caused by water and soil conservation measures,when the years with similar rainfall in Per3 and Per1 periods,the sediment discharge in these years in Per3 period was significantly reduced compared with that in Per1 period,with a reduction range of 50.2%~98.6%;(3) During the period of 1987-1999,the contribution rates of vegetation restoration and soil and water conservation measures to the reduction of sediment discharge were 73.0% and 38.4%,respectively.during the period of 2000-2015,the contribution rates of rainfall change,vegetation restoration and soil and water conservation measures were 11.5%,69.8% and 18.7%,respectively.The results of this study quantitatively calculate the contribution rate of rainfall variation and soil and water conservation measures to the reduction of sediment discharge in the Huangfuchuan River Basin,which is helpful to identify the causes for the sharp reduction of sediment discharge in the middle Yellow River.