In recent years, Gulin river water quality was becoming worse. In order to acquaintances spatial and temporal distribution characteristics of non-point source pollution and critical?source?areas (CSAs) in Gulin River Basin. Firstly, the fractal theory was used to determine the most suitable threshold of drainage area (TDA) .On?this?foundation,this paper study the migration and the pollution load of non point source pollution in the rural area of the Gulin River Basin based on SWAT model,the results show that: the most suitable threshold of drainage area is 1500ha and the basin was divided into 37 sub-watersheds;the monthly average runoff and nitrogen and phosphorus load of the model simulation evaluation index Nash coefficient was greater than 0.5, and the decision coefficient R2 was greater than 0.6, so the SWAT model has good applicability in the research area;in 2013 ,the output of TN in Gulin River Basin was 2761.72t, and the output of TP was 338.27t; the pollution load of Gulin Town, Deyue Town, Xiang Shiping accounted for a larger proportion and the ranking of the contribution rate of the pollution sources in each sub basin were all chemical fertilizer > livestock breeding > domestic?pollution,Therefore, the agricultural chemical fertilizer ,Gulin Town, Deyue Town, Xiang Shiping were the key point for the prevention and control of the non-point source pollution in the basin.