Abstract:In order to evaluate direct influence of minimum purchasing price policy on the price fluctuation of wheat in China,this paper employs the spot and futures wheat prices data between January 4th,2009 and December 30th,2016 to empirically study the impact of policy on stabilizing the volatility of spot and futures wheat prices by using the policy as dummy variable into the GARCH model and compares the effect of policy execution in maintaining stability of wheat prices in different areas from the perspective of policy execution area and nonpolicy execution area. Finally this paper tests and analyzes the model result and price transmission path. The result shows that policies have obvious influence on the fluctuation of spot and futures wheat prices,which can significantly lower the wheat spot price volatility and affect the futures market through the connection between spot market and futures market. However,the effect of policy on fluctuation of futures price is reverse.The price-stabilizing effects of the policy has a spillover effect in the space. Transformation of regional market connection from policy execution area to the nonpolicy execution area will cause the decrease of price volatility in the non-policy execution area.