The characteristics, present situation and causes of soil and water erosion in Xuanwei city, a model of soil and water conservation, in Yun'nan province are analyzed. The results indicate that the building of plant check dam in erosion gully is able to improve the way to harness the erosion gully and decrease the cost of soil and water control in severe soil erosion areas. The right classification of soil and water conservation will be useful to strengthen soil erosion control of the key area, and promote the combination between preventing and harnessing of soil erosion.