Objective: To compare the results of two rounds of colorectal cancer screening in Haining, explore the long-term mechanism and interval time of screening during the prevention and control of colorectal cancer, and establish practical basis for the rational prevention and control strategies. Methods: Between 2007 to 2010 and 2013 to 2015, a total of 80, 000 cases who had completed two rounds of tumor screening were enrolled and analyzed. All cases comes from five towns in Haining. Results: The first round of screening was performed in 80 603 cases and 12.92% (n=10 417) were identified as high-risk population. Colonoscopy were completed in 7 796 subjects and 22.05%(n=1 719) of them were found at least one neoplastic lesions (polyps, adenoma or carcinoma). The population detection rate of all neoplasia was 21.33 per thousand. The detection rate of advanced neoplasia was 4.58% per colonoscopy and 4.43‰ in the population. A total of 357 advanced neoplasia including 296 advanced adenomas and 61 colorectal cancers were found, 330 of whom were applied to early treatment (92.44%). A total of 89 403 subjects participated the second round of screening. The detection rate of high-risk population in the second round (20.81%) was significantly higher than that in the first round (P<0.05). A total of 12 917 subjects completed colonoscopy and 31.97% (n=4 129) of them were found as least one neoplastic lesion. The population detection rate of all neoplasia was 46.18 ‰. Both in the subjects completed colonoscopy and in the screened population, the detection rate of all neoplasia were significantly (P<0.01) higher than that of the first round. The detection rate of advanced neoplasia (n=851) in both the subjects completed colonoscopy (6.59‰)and the total screened population (9.52‰) in the second round were also significantly (P<0.01) higher than that of the first round. The difference of early detection rates for the first (92.44%) and the second (97.53%) round screening were not statistically significant(P>0.05). Conclusions The main technical indicators of the second round of colorectal cancer screening were significantly better than that of the first round, with significant screening effect. A screening interval of 5 years was suggested for the next round of colorectal cancer screening.