On the basis of investigation in the field and observation in experimental stations,the benefits of soil andwater conservation about returning cropland to forest in Wuqi County are analyzed and studied quantitatively.Results show that vegetation coverage is obviously increased by returning cropland to forest and grazing prohibition inmountains,physical and chemical characters of soils are greatly improved,vegetation communities are becomingstable gradually,and the amount of soil and water loss is kept within limits.Thus it can be seen that measures ofreturning cropland to forest and grazing prohibition in mountains are the effective approach to control soil and waterloss in loessy hilly region.