Abstract:Annualized Agricultural Non-Point Source model (AnnA GN PS),a continuous-simulation water-shed-scale model ,is widely used to evaluate non-point source pollution in agricultural watersheds in a number of countries. The Daning River watershed in the Three Gorges Reservoir Region was selected as a case stud-y. The model was parameterized based on landuse,soil,topographic data,and eight-year climatic data. Di- rect runoff was derived from the observed runoff using the baseflow filter method. Then indicators such as percent error (PE) , Nash2Sutcliffe coefficient (NS) , determination coefficient r2,and gradientk were used to evaluate the performance of AnnA GNPS. The calibration result for runoff is very satisfactory ( PE =-3.71%,r2=0.94,k=1.04,and NS=0.94).The validation result also matches well with the observed data,with PE=-6.37%,r2=0.93,k=0.93,and NS =0.94 for runoff and PE=-16.5% for sedi-ment yield. Alternative scenario simulations show that converting cultivated land into forest is promising BMPs (Best Management Practices) for sediment reduction. The results demonstrate that the model is suit-able for prediction and assessment of runoff and sediment from the watershed.