Based on the material of investigation and experment,according to some relevant indexs,12.43×104hm2 of transforming slope into terrace project in Qinghai province which constrcted in 1994, is quantitatively analysized about the input and output.Thereby,the benefits of socity,economy and ecology of the project is confirmed scientifically.It is fully illustrated that the project play an very important role in controlling soil and water loss,in improving the ecoevironment,it has a practical significance for promoting the crop yield of Qinghai province to reach a new step,and for promoting the economical development and taking the mountainous people from poverty to wealth