Abstract: AGNPS (Agricultural Non Point Source) model is a computer model specialized for predicting and evaluating the agricultural non point source pollution of a watershed. To evaluate the feasibility of AGNPS model applied to watershed ecosystem in hilly areas of southern China,the results of phosphorus losses from field observed and from AGNPS predicted were compared in Paixichong watershed belonging to red soil hilly areas, located in northern Zhejiang Province,southern China. The study showed that the predicted results coincide with observed results, which suggests that this model is suitable for predicting phosphorus losses in red soil hilly areas,southern China.