Abstract: The effect of market-oriented reform of maize purchasing and storage system has important reference significance for the improvement and reform of other grain policies. Based on the monthly panel data of the provincial level from October 2008 to December 2017, this paper estimates the impact of the market-oriented reform of maize purchasing and storage system on the price fluctuation of maize by using the double difference method.After peeling off the influence of other factors on price fluctuation, it is found that the market-oriented reform of maize purchasing and storage system can reduce the volatility of maize price by 0.76 percentage points in three northeastern provinces and one region. The mechanism analysis shows that the market-oriented reform of maize purchasing and storage system balances the supply and demand of maize in three provinces and one region of Northeast China, stabilizes the price fluctuation of maize in Northeast China, while the non-reform area has not implemented corresponding policies, which leads to the difference of price fluctuation between two regions;at the initial stage of market-oriented reform of maize purchasing and storage system, the price volatility of three provinces and one region in Northeast China could be reduced by 1.32 percentage points, but this effect gradually weakened with the passage of time.

Key words: maize, market-oriented reform of purchasing and storage ystem, price volatility, difference-in-differences