The characteristics of runoff and sediment and their changes in Jinghe watershed.were analysed in detail, According to the basis‘laws of forming runoff and sediment, the hydrological method was used to calculate the benefits of runoff and sedi-ment reduction, It was concluded that durng 1970}1989 the benefits of runoff and sediment reduction account for 7,5 percent and 14,4-。en respectively through the comprehensive control on the watershed, and the influence f runoff and sediment.reduction for 32 percent and 48 percent respectively by the reduced precipitation, C3ood_identity is found between the results of hydrological method and the ones of im plementing the measures of soil and water conservation, After of the sharp reduction of sediment in 1980s, it was indicated thsediment reduction are reduced precipitation, The influences anvaysing the causes at the mayor causes of redued precipitation and comprehensive control on sediment reduceion are respectively,about gg percent and 37 percent