Soil erodibility serves as a major parameter for soil erosion prediction and land use planning.Olson and Wischmeier gave it a very clear definition which has been used in many soil erosion models.However,it is not suitable for China.Based on the review of the 70 years research achievements on soil erodibility,and in light with China's actual conditions on land use as well as the available erosion data,the definition on soil erodibility index and its measurement in China was developed The soil erodibility for China might be defined as the average soil loss per unit of the erosion index from the clear tilled fallow on a plot 20 meters long on a slope of 15° This defi nition may help us for field measurement and Chinese soil erosion prediction model deve lopment.