Analysis on Mechanism of China's Grain Production Development and Evolution From 1985 to 2019

China's grain production has been on a pathway paralleled with urbanization in recent 40 years, from lower efficiency and productivity to the higher ones, and has met complex impact factors and contradiction between sustainable development of farming and urbanization. Spatial-temporal pattern of grain production in China, by total and per capita output, was analyzed through Local Moran'I from 1985 to 2019. Until 2019, the high-output countries were mainly aggregated in the main plains and basins on the third step of China's terrain and the low-output areas increased in the southeastern coastal regions; the countries with high per capita output almost disappeared and the low areas increased a lot in the central and southern regions Then the impact factors, by total output in the whole country and in grain surplus-shortage regions, were detected and found out through Geodetector. In the whole country, cultivated land areas, agricultural machinery, total meat output and value-added of primary industry not only played important role independently, but also had mutual coupling effect in grain total output. And in the grain surplus regions, major factors were cultivated land areas and value-added of primary industry, while in the grain shortage regions, were labors and market as well as economic factors. Thirdly, factor mechanism of China's grain production for four types of development orientations, i.e., orientation on production scale, production efficiency and benefit, product quality and economic coordination, were concluded, and the way of grain production in different regions with unique suitability and advantage were expounded.