Objective:To investigate the prevalence of the high-risk populations of colorectal cancer（CRC）in Chongqing

and to improve the rates of early diagnosis and early treatment of CRC. Methods:The residents aged from 40 to 74 years old in Chongqing urban area were preliminarily screened with the questionnaire survey and fecal occult blood test（FOBT）

and the high-risk populations screened out were examined by the colonoscopy voluntarily. The CRC screening rates and detection rates were assessed. Results:Totally 2 957 cases were preliminarily screened

513 cases were screened out as the high-risk of CRC populations. The positive rate was17.35%. Among the high-risk populations

278 cases were examined by the colonoscopy. The colonoscopy screening rates was 54.19%.One hundred and thirty-four cases were found colorectal disease

including 2 cases of colorectal cancer

31 cases of pre-malignant lesions

and 101 cases of benign lesions. The detection rate was 48.20%. Conclusion:The questionnaire survey with the FOBT can effectively discover the high-risk population of colorectal disease and precancerous. The colonoscopy is recommended afterwards so that we can achieve the early diagnosis and early treatment of CRC.