Abstract: After introducing grain subsidy policy in 2004, the grain production and farmers’ income level in Beijing have been boosted considerably. The scientific assessment on the effects of subsidy policy is the prerequisite for future optimizing and implementing preferential policies for agriculture and farmers. This study firstly summarizes the history and characteristics of Beijing’s grain subsidy policy, based on related government documents and statistical data. Then DEA modeling is employed and questionnaire results are analyzed. The results indicate that the efficiency of grain subsidy policy in Beijing is at high level, but there is still some room for improvement. The policy is implemented well with sound public opinion, but still some problems exist. At last, several policy recommendations are put forward for further policy optimization.