Pennisetum pureum is a perfect kind of grass with excellent soil and water conservation property. However, few quantitative studies on its soil and water conservation have been done. To probe into the effects of Pennisetum pureum on soil and water conservation, the capability of water conservation in the vegetation,the content of water in the soil, soil anti-scouribility and penetrability are measured. The result shows that Pennisetum pureum is strong on the capability of water conservation in the vegetation can improve such soil features and enhance the content of water in the soil greatly; so it can be widely used for soil and water conservation purpose in the area of Three Gorges.