At present，our country is facing multiple constraints of food supply，namely，rigid growth of consumption，deterioration of the ecological environment，hardness supply of resources.One of the useful ways to ensure food security is to reduce post-harvest food losses to increase the effective supply of food.This essay takes the 1662 food vendors in 9 Provinces as the research object，and uses Tobit regression model to analyze the main factors influencing post-harvest food losses in marketing chain.The results show that the factors in storage stage have great impact on food losses，second is in transit stage，food losses in exhibition stage is minimal.Influencing factors of negative correlation with food losses in marketing chain include level of education，working time，storage conditions of food，and market supply of public facilities and the level of management.Influencing factors of positive correlation with food losses in marketing chain include age，separation of food store and storage，and autumn.