Abstract: Grain price support policy is an important regulating policy for ensuring grain supply in China. Based on the panel data of the price, output, and demand of wheat, rice, and corn from 2000 to 2013 from both producing and consuming regions, taking supply and demand, cost, and policy factors, as well as dummy variables and cross variables in the model, this paper examined the effect of price support policies on stabilizing the market prices of wheat, rice, and corn and the regional effect in producing and consuming regions. Result shows that staple grain price support policies have stabilized the market prices to a certain degree. Wider geographic policy coverage and stronger execution support market prices more significantly. The effect of staple grain price support policies does not have an obvious regional difference. This means that the policies did not bring adequate compensation to major grain producing areas; instead, regional imbalances between supply and demand for staple grain is enlarged, making staple grain prices in some consuming regions too high. To enhance the effects of the price support polices, this paper provides the following suggestions: reducing grain production costs by expanding the scale of operations, launching marketing oriented grain price support policies, and increasing subsidies in main grain producing regions.