Abstract: Objective To investigate the risk factors of colorectal cancer.Methods A 1:2 controls data were analysed with conditional logistic regression.Results That the diet frequency of meat,the frequency of using oil of animal ten years ago and salted meat,the poor ability of adjusting the mood,the history of gastric and duodenum ulcer and chronic appendicitis,and collateral relatives who suffered from cancer were independent risk factors of colorectal cancer.The corresponding OR was 1.114,1.091,1.117,1.490,2.483,5.751 and 11.531,respectively.Favor of eating soft food was an independently protective factor,and the corresponding OR was 0.789.The history of falling ill in respiratory system and coronary heart disease were negatively related risk of colorectal cancer,and the corresponding OR was 0.230 and 0.441,respectively.Conclusion Colorectal cancer seemed to be related to the dietary factors,the poor ability of adjusting the mood,the history of gastric and duodenum ulcer and chronic appendicitis,and family history of malignant tumors.