Objective To study clinical characteristics and treatment after colonscopic perforation， and to determine risk factors for postoperative complications. Methods Cases diagnosed as colonoscopic perforation within 7 days after colonoscopy in Peking Union Medical College Hospital between January 2010 and January 2017 were reviewed. Data regarding demography （age， sex）， clinical information （comorbidities， medication history of glucocorticoid， length of hospital stay）， colonoscopy （whether endoscopic therapy or anesthesia was performed， intestinal cleanliness）， perforation （region， diagnosing time） and operation （laparotomy or laparoscopic operation， procedure， post-operational complications） were collected. Single factor analysis and Spearman correlation analysis were employed to determine the risk factors of postoperative complications. Results A total of 14 colonoscopic perforation cases were identified and included in this study， and the overall perforation rate was 0.03％。Most perforations occurred in rectum （2 cases） and sigmoid colon （8 cases）. Twelve perforation patients received operational treatment， of who 6 developed postoperative complications， including 3 cases of incision infection， 2 cases of peritoneal infection， 1 case of catheter-related infection and 1 case of pulmonary embolism. Spearman correlation analysis showed that preoperative medication of glucocorticoid and non-rectosigmoid perforation were positively related to postoperative complications （both correlation coefficients were 0.707， P=0.01）， while perforation diagnosed immediately and satisfying intestinal cleanliness were negatively related to it （both correlation coefficients were -0.667， P＜0.05）. Conclusion Perforations are rare but severe complications of colonoscopy， and surgical interventions are necessary in most cases. Postoperative complications were significantly related to perforation sites， preoperative medication of glucocorticoid， perforation diagnosis time and intestinal cleanliness.