Abstract: Objective To investigate risk factors of colorectal cancer in community residents,and provide the basis for the early cancer detection. Methods A self-administered questionnaire based on cancer risk assessment systems that modified from Harvard Cancer Risk Index were used in the survey.The community residents aged 40 to 69 of seven administrative region of Hefei were assessed.The high-risk population were then suggested to do further colonoscopy check and clinical screening to detect colorectal cancer or precancerous lesions.Disease or health as the dependent variable,the related risk factors were analyzed by binary logistic regression method. Results Total 4 696 people (15.78%) in 29 750 cases were detected for colorectal cancer risk factors by Harvard Cancer Risk Index evaluation.There were significant differences between the sexes,and between the age groups in 40-44 and 65-69 year (P<0.05).The prevalence in group of 40-and 50-were significantly higher than group 60-.One colon cancer and eighty-six precancerous lesions cases were found by clinical colonoscopy examination.Multivariate logistic regression analysis showed that chronic colonic enteritis,gastrointestinal disease,hepatitis C,high blood pressure were the risk factors,and service industry,passive smoking,hepatitis B were protective factors. Conclusion It is conforming to the principle of early disease prevention and health economics with assessing risk of colorectal cancer by disease health index of lifestyle and then doing clinical examination for the high-risk,which promote the residents'attention of early detection and treatment.Treating chronic colonic enteritis,hepatitis,especially hepatitis C actively,learning healthy lifestyle could be beneficial to the prevention of colorectal cancer.