Based on UN Comtrade Database of agricultural products and Revealed Symmetry Comparative Advantage(RSCA) index,this paper analyzes and compares the dynamic changes of agricultural products’ comparative advantages before and after China’s entering WTO by using the non-parametric Kernel Density Estimation and Conditional Density Estimation.The empirical results show that the comparative advantages of China’s agricultural products are still not so good before and after its entering into WTO.Around this 20 years,there have been quite significant changes of agricultural products’ comparative advantages and trade patterns,and these changes have become even more obvious after China’s entering into WTO.This paper finally concludes that some strategies for improving agricultural comparative advantages should be made so as to escape from the comparative advantage trap.At the same time,risk prevention mechanism must be established to improve the risk resistance capacity in international agricultural market when sharing the bonus of globalization.