Soil erosion, as a global environmental problem,has been paid more and more attention. It is very important to dynamiealy simulate and forecast the development and evolutionary process of soil erosion. Cellular Automata（simple named “CA”）is a dynamic modeling framework,being capable to simulate the spatial-temporal evolutionary process of geographical complex system. It was introduced that the concept and the characteristic of CA theory and its application in soil erosion. Some present problems were discussed. The feasibility was proved while CA model was applied to simulating and forecasting the process of soil erosion.