Abstract: Flood and drought are important factors which influence stable supply of major grain-producing areas, and threat food self-sufficient security in China. In this paper, flood and drought risk of 13 major grain-producing provinces were assessed by using information diffusion theory. Flood and drought risk level was analyzed under four different of hazard context. At the same time, flood and drought risk conditions were systematically compared, as well as time-space distribution. The results showed that, pressures of flood and drought risk in 13 major grain-producing provinces were all bigger, and drought risk was more serious than flood risk. Flood risk was more serious in southern major grain-producing province and drought risk was more serious at northern and the Yellow-Huaihe-Haihe Plain in major grain-producing province of China. The study on risk assessment of flood and drought provides support for risk prevention and decision-making.