According to the general structure of the risk early-warning System,this article analyzes the subsystem which composes the risk early-warning in rapeseed industry.Based on the factors influence rapeseed supply and demand,macro economy,national policy,world market price and other factors affecting the point of rapeseed,the risk pre-warning index system of China’s market price of rape industry was constructed with the rapeseed purchasing price volatility as risk pre-warning indicators of the rape industry in this paper.Through the empirical study of the rape industry risk pre-warning by using BP neural network and the sample of 1990-2007,the risk pre-warning model constructed by BP neural network is proved to be practical and feasible,and an effective risk pre-warning model of China’s rape industry is provided.