Abstract: A major inducement of food safety accidents is the unbalanced supply-demand relation in food logistics. Based on logistics balance,this paper builds a food risk propagation model which simulates a complete supplier-to-consumer chain,and then analyzes how different supply-demand relations effect the food safety and the decision-making of individual actors,by using computational experiment. The research resups explain the inevitability of some current food safety accidents from logistics balance dimension,and reveal that different supply-demand relations lead to different level of food safety. Specifically speaking, the higher tension there are,the higher risk there will be. In the case of an extreme unbalance supply-demand relation,government regulation can,only control malignant spread of hazardous substance in a limited extent rather than guarantee it fundamentally. Comparing and contrasting with static supervision,the flexible and dynamic regulation is more efficient in food safety control. In addition,logistics relation and regulatory strategy effect the upstream of food supply chain deeper than it that on downstream.

Key words: supply-demand relation, food supply chain, government regulation, computational experiment, logistics balance