In Loess Plateau,soil erosion is very intensive,and the actual productivity is low.To study the region's crop yield potential can offer grounds for increasing crop yield and conducting agricultural production programming.This paper introduces the characteristics,component,and application procedure of EPIC,and revises some crop parameters.Taking the maize and wheat as example,we proved that there is a good adaptability for EPIC model to be used in Loess Plateau for crop productivity simulation research.The results indicated that the average deviation between simulated and measured values for wheat was7.78%,that for maize9.60%;the number of annual average water stress days of wheat was9.9,the minimum was1.7,the maximum was23.1,that of maize was13.4,1.1,22.1.These values are in accordance with actual rainfall condi tions of the growing period of the above mentioned crops.The revised model is very accurate in normal years,but it is necessary to improve the revision method of the crop and soil parameters in arid years.