Abstract: Objective To explore tne relevancy between diet and the pathogeny of digestive system cancers and offer the scientific bases for cancer prevention.Methods 66 diagnosed cancer patients were taken as research cases and 132 cases of the same sex and age were picked up randomly as a non-cancer control group to carry out a 1:2 matched case-control study.By condition Logistic regressive analysis,the main risk factors were screened out among 26 potential diet factors related to the cancer.Results Addiction to pickles,fries,smoked foods,animal oil,preserved pork and hot diet were risk factors for digestive system cancers.Preference for greens,fruits,fresh meat and milk were protective factors.All factors above based on the statistic evidence(P<0.05 or P<0.01).Conclusion Diet factors have a close relevancy with the pathogeny of digestive system cancers.Proper diet in daily life should be kept and the inappropriate living and diethabits should be changed.