Abstract: China is a major grain-producing and consuming country, and food safety is an important matter concerning the national economy and people's livelihood. In recent years, the mycotoxin contamination in grains has become increasingly serious, posing a threat to national food safety. To achieve precise prediction and control of mycotoxin contamination, researchers have carried out a large amount of basic research and made great progress in the research of the relationship between toxigenic fungi and mycotoxin contamination. This paper summarizes the main types and hazards of toxigenic fungi and mycotoxins that contaminate grains, with a special emphasis on the relationship between grain toxigenic fungi and mycotoxin contamination and the distribution pattern of toxigenic fungi and mycotoxins in grains in China, discusses the mechanism of mycotoxins priduction of toxigenic fungi and its influencing factors based on the relationship between toxigenic fungi and mycotoxin contamination and suggests the preventive and control measures for mycotoxin contamination in grains in order to provide reference for the further study of the complex relationship among toxigenic fungi, mycotoxins and environmental factors and provide theoretical evidence and guidance for the early warning, prevention and control of mycotoxin contamination in grains, as well as detoxification technology research.