Objective To assess the efficiency and safety of endoscopic submucosal dissection （ESD） on treatment of colorectal lesions. Methods Clinical data of 163 patients with colorectal lesions， who underwent ESD at Endoscopy Center of Peking University First Hospital from June 2012 to June 2016， were retrospectively analyzed. The clinicopathologic features， the rate of en bloc resection， complete resection， complication and recurrence were reviewed. Results Among the 163 colorectal lesions， 118 were mucosal lesions and 45 were submucosal ones. The mucosal lesions included 31 cases of protruding type， 22 of flat type and 65 of laterally spreading tumor （LST）. The submucosal lesions were all protruding type. The median lesion diameter was 2.2（2.0） cm， median operation time was 42（53） min. En bloc resection rate was 92.6％ （151／163）， and complete resection rate was 86.5％ （141／163）. The risk factor related to en bloc resection rate and complete resection rate was tumor size （P＜0.05）. Complications occurred in 4 cases， including 2 cases of intraoperative bleeding and 1 case of delayed bleeding who received endoscopic hemostasis therapy， and 1 patient with delayed perforation， which was managed by emergency surgery. Four recurrences were observed in 135 cases during follow-up， of which 3 were cured by additional endoscopic treatment， and 1 by surgery. Conclusion ESD is a safe and effective， but less invasive technique for colorectal lesions. Favorable long-term clinical outcomes can be achieved when en bloc curative resection is performed.