Abstract: Grain consumption is a main component of grain security. Based on the actual production and consumption of grain in Jiangsu from 2000 to 2016, this paper analyzes the changing characteristics and influencing factors of grain consumption, and discusses the sustainability of maintaining the balance of domestic grain supply and demand through the change of contribution index of grain security in Jiangsu. Results show that grain consumption in Jiangsu increased steadily and slowly from 2000 to 2016, and the average annual growth rate of grain consumption was only 0.04 percent, lower than the average annual growth rate of grain output in the same period. Compared with the decreasing grain ration, the feed grain and industrial grain have gradually become the new growth points of grain consumption. The development of urbanization, industrial construction and “inversion of price” leads to a rapid growth of demand for grains, which imposes a threat to grain security. In terms of the total grain quantity, the contribution index of Jiangsu Province displayed a decrease-increase-decrease pattern, indicating that Jiangsu Province cannot continue to play a key role in domestic grain security. From the variety structure perspective, the supply of corn in Jiangsu is lower than the demand, helping reduce the high stock level of corn. Although the production of rice and wheat can help improve domestic grain security, there are still worries about the potential high stock level and the structural imbalance between supply and demand of grains. Therefore, providing multi-directional choices for grain supply, encouraging farmers to grow grains in a demand-oriented way, and making full advantage of two markets and two kinds of resources have become important means for Jiangsu to deal with the grain crisis.