Impacts of the minimum purchase price policy for grain on the planting area of rice in Hubei Province were analyzed based on a mixed linear model. After the indicator system containing the minimum purchase price policy and other factors influencing the planting area of rice was constructed, principal component analysis of the system was conducted, and then a mixed linear model where the planting area of rice was as the dependent variable was established. The results show that to the exclusion of the interference from other factors, the minimum purchase price policy for grain had a positive impact on the planting area of rice in Hubei Province. That is, the minimum purchase price policy significantly stimulated the growth of rice planting area in Hubei Province.