On the basis of SOTER, running SWEAP could get some conclusion. The soil erosion in Hainan mainly occurred in sloping land and steep land. Soil erosion spatial distribution was identical with Hainan landform. There were higher soil erosions in the mountainous areas of centre Hainan, and there were lower soil erosions in the coastal area of north of island. For the sloping land, terracing or strip cropping could be suitable to reduce soil erosion. The result also showed: under the support of SOTER, it was credible and useful that using SWEAP assessed soil erosion in Hainan.