Abstract:Based on the study of long series hydrological and precipitation data from 1960 to 1999 and analysis on time variation tendency of annual sediment delivery and annual precipitation of the Dalihe river basin,the paper finds that sediment yield has been increased in the period of 1986~1999 based on the overall condition of reduction in the region since 1972.The increasing tendency is closely related with the situation of the reduction of check-dams building since 1980's and lost effectiveness of most reservoirs for sediment retaining built in 1970's.In addition,the man-made sediment increase is great in 1990's,making up about 20% of sediment reduction through soil and water conservation measures and partially counter acting sediment reduction benefits gained through soil and water conservation measures.This is an important reason why the sediment yield is increased in 1990's.Therefore the paper puts forward some counter measures and suggestions in accordance with existing issue such as putting stress on the sustainable construction of the check-dams,cooperating with all kinds of ramp measures,paying attention to new added soil and water problems and so on.