Objective To investigate the result of colonoscopic positioning in laparoscopic treatment of colon tumors . Methods A retrospective analysis was made in 16 cases of colon tumors treated with laparoscopic colon resection from January 2014 to November 2015.During the operation, the lesion could not be locatized and the resection range could not be determinated because the serous layer was not involved or the lesion was located in the lateral abdominal wall .Transanal colonoscopic positioning of the lesion with light transmission method was carried out . Results The pathological changes were found under colonoscopy in all the 16 cases and the laparoscopic resection was successfully completed without conversion to open operation .No missed resection or incorrect resection occurred.The operation time was (112.5 ±31.0) min and the blood loss was (22.8 ±11.2) ml.Among 9 cases of preoperative pathological diagnosis of benign tumors , there were 6 cases of malignant tumors after surgery , including 4 cases of moderately differentiated adenocarcinoma , 1 case of moderate to severe atypical hyperplasia with cancerous lesions , and 1 case of moderately differentiated adenocarcinoma with mucous adenocarcinoma .A total of 15 patients were discharged from hospital at 12-24 days after the operation , whereas 1 patient was dismissed 1 month after the operation due to anastomotic fistula .The 16 patients were followed up for 3 months with no recurrence under colonoscopic examiantion . Conclusions During laparoscopic colon resection , if the tumor can not be locolized , colonoscopic positioning can help prevent missed resection or incorrect resection , which increases the indication and safety of laparoscopic and colonoscopic minimally invasive treatment .It has good clinical application value and deserves further promotion .