Abstract： Objective To evaluate the accuracy and value of the placement of metallic clips during colonoscopy in the localization of colorectal cancer and incision selection. Methods A total of 30 patients received metallic clip placement by colonoscopy before operation. Abdominal plain film (supine and upright position) was taken and incision was determined by the projection of clips on the abdominal wall. Results The inaccuracy rate of localization by colonoscopy was 30%(9/30).Colonoscopy combined with the placement of metallic clips achieved an accurate incision rate of 100% (30/30). Conclusions There is a considerable rate of inaccuracy for localization in colonic cancer by colonoscopy. Colonoscopy combined with placement of metallic clips should be considered in order to select a reasonable incision.