To study the comparative advantage of main crops in Shanghai, we first improved the traditional method of measuring comprehensive advantage.Then we used the improved comprehensive advantages indices method to analyze the efficiency advantage indices, the scale advantage indices, the labor advantage indices, the mechanization indices, the market infrastructure advantage and aggregated advantage indices of four crops.Results showed that the order of aggregated advantage was:rice, wheat, soybean, corn.In the end, we gave some suggestions on adjusting the structure of crops’ planting in Shanghai.