To ensure the future food self-sufficiency in China, it is necessary to mobilize producers' enthusiasm for growing grain. Theoretically, it is mainly influenced by economic interests, land scale, farmers' characteristics and agricultural support policy. Through field research of farmers, we use model to explore these influencing factors. The results show that the dwindling arable land making grain cultivation fail to form economies of scale is a key factor restricting farmers' enthusiasm for growing grain; farmers' age and the share of agricultural labor in the family are important factors restricting their grain growing; agricultural support policy can stimulate the enthusiasm for growing grain to a certain extent. Therefore, there is a need to promote the concentration of land and improve various agricultural support policies, in order to improve the economic benefits of growing grain and encourage qualified young workers to engage in grain production activities.