In current Chinas grain supply and demand market, because governments still undertake the main task for purchasing grain, buying and selling price in the market is still something of monopoly, furthermore, because of this monopoly, the main body of Chinas grain purchasing market shows dual structure. As rational market subjectivity, the governments consider more about residents life insurance and grains price stability. Thus, under current situation, it is main reason for Chinas grain price vibration that the governments reduce subsidies and reduce market balance price. The behaviors of the government make the peasants lose activity to produce grain, which leads to rare land resources to be difficult to realize reasonable allocation and scientific use.