With the development of the rural economy in China, rural household's consumption behavior in main grain producing area has being changed, which influence the adjustment of Agricultural industrial structure and agricultural industrial policy. In this article,we use Almost Ideal Demand System(AIDS) to estimate the elasticities of demand expenditure and price(own price elasticity and cross-price elasticity) and then to analyze food consumption behavior of rural household in main grain producing area. The results show that foods such as rice, wheat, pork, beef in main grain producing area have the positive elasticities of demand expenditure. According to the cross-price elasticity, the demand for eggs, mutton, beef and pork is more affected by the fluctuation of other food's price, while the demand for the wheat, rice, maize and soybean is less affected by thefluctuation of other food's price. Based on the results, some policy recommendations, such as increasing farmer's income, expanding the animal food production, stabilize food's price, are put forward correspondingly.in the article.