To explore the reasonable devotion that is agricultural factor of grain production of Jiangsu Province and the 3 major regions, based on the economic regionalization results in Jiangsu Province, the paper calculated the grey relevancy between grain output and the elements of agricultural production in Jiangsu Province and the 3 major regions. The difference of the mean value of input element of grain production in the 3 major regions was tested by using Kruskal-Wallis examination method, and analyzed the regional disparities. Results indicate the obvious difference of the correlative degree and the correlation order between grain output and the elements of agricultural production from the various regions, the difference of the mean value of input element of per-unit grain output also differ in different regions. At the basic of that, this paper thinks that Jiangsu Province grows stable grain the area, develop large-scale management, implement the agricultural benefits of policy, and increase the level of unit production to make sure the steady growth of grain production in Jiangsu Province.