Based on an integrated scientific review of soil and water erosion and ecological security in China, the method for potential hazard degree evaluation of representative water erosion region in China based on GIS is proposed, and the whole technological process of potential hazard degree analysis and evaluation is summarized. Practice has proved that the evaluation result is reasonable, basically. The study can be used as a reference to the studies of potential hazard degree evaluation of soil erosion and the GIS development for soil and water conservation.