Abstract: This paper explores both the theoretical and empirical function of prices upon grain production in China. Because farms maximize their gains from grain production, the price of grain and the price of agricultural production means will affect grain production. Through theoretical and empirical analyses, we found that the series of yield of grain, sown areas of grain, price index of grain and price index of agricultural production means are cointegrated. The action of price expectation also shows lag cointegration and contemporaneous cointegration among these series