Objective To investigate the clinical and pathological features of patients with colorectal lesions, which could be the basis for clinical diagnosis and treatment of early colorectal cancer. Methods The clinical ( including gender, age, size, location, morphology, and number ) and pathological characteristics of colorectal lesions were discussed based on the results of colorectal cancer screening in more than 320000 people of 40-74 years in Haining from 2007 to 2012. Results Screening of 286470 cases were completed with the compliance rate of 88. 96％. Colonoscopy was performed in 29069 cases, and 7408 lesions were detected with detection rate of 25. 48％. The detection rate was 32. 62％ for men and 19. 48％ for women ( P<0. 001 ) , and 18. 30％ in 40-49 age group and 35. 06％ in 70-74 age group. The older the patients, the higher the detection rate ( P<0. 001) . Among the 7408 lesions, left colonic lesions accounted for 69. 40％, multiple lesions accounted for 37. 23％, lesions with diameter>1. 0 cm accounted for 19. 60％. A total of 205 cases of colorectal cancer ( including 161 early carcinoma and 44 advanced carcinoma) , and 1365 cases of advanced adenoma were found. The early diagnosis rate was 97. 20％. Among the 5030 lesions underwent treatment, adenomatous and carcinomatous types accounted for the largest proportion ( 63. 00％) . The canceration rate of lesions with diameter >1. 5 cm was 34. 08％. Conclusion In high-risk populations, men have a higher detection rate of colorectal lesion than female. The older the age, the higher the detection rate. Adenoma account for the highest proportion among different pathologic types.