This paper describes the mechanism of dynamic monitoring of soil erosion with remote sensing technology, and establishes the interpretation keys for soil erosion degrees in Southern China. Analytical results based on the dynamic monitoring maps of soil erosion at three historical periods and the investigation and statistic data from Xingguo and Yuexi counties showed a parabolical type change of soil erosion in the mountainous and hilly areas of south China. It has an evident decreasing tendency of the soil erosion area in Jiangxi, Fujian, Hunan and Guangdong provinces of China.