Taking shaanxi heihe river watershed as study region,AnnAGNPS(Annualized Agricultural non-Point Source Model) foundation database was established using GIS(Geographic Information System) and relevant data to extract parameter.The model was calibrated and validated using observed stream flow,sediment load,inorganic nitrogen and total phosphorus month data from 1991 to 1998 at the Heiyukou section,which was used to judge the adaptability of the model in typical watershed in semi-arid region of Northeast of China.The results showed that the model could be used to long term simulation of the watershed NSP(non-point source pollution).Subsequently,Sensitivity of main parameters of the model was analyzed.Finally,the validated model was used to simulate the management measures.The result showed that the reforestation project,which simultaneously minified the amount of runoff,sediment,total nitrogen and total phosphorus should be adopted in Heihe watershed in order to control NSP.