ObjectiveTo investigate the risk factors of duodenal papilla hemorrhage after endoscopic papillary balloon dilatation (EPBD) for choledocholithiasis. MethodsClinical data of 411 cases of choledocholithiasis treated by EPBD in Hangzhou First People′s Hospital from January 2016 to December 2019 were analyzed retrospectively. Based on the development of hemorrhage after EPBD, patients were divided into the hemorrhage group and the non-hemorrhage group. The risk factors of hemorrhage after EPBD were analyzed by single and Logistic regression. ResultsAmong 411 patients who received EPBD, 29 patients had EPBD-related duodenal papilla hemorrhage and the overall incidence was 7.1%.Univariate analysis showed that there were significant differences between the hemorrhage group and the non-hemorrhage group in diameter≥1.2 cm of balloon dilation （P=0.001）, endoscopic sphincterotomy (EST) （P=0.002）and the incision length of EST （P＜0.001）. Logistic regression analysis showed that the incision length of EST (OR=69.771, 95%CI: 7.544-645.296, P＜0.001) was the independent risk factor for duodenal papilla hemorrhage after EPBD. Diameter≥1.2 cm of balloon dilation(OR=0.192，95%CI： 0.071-0.524， P=0.001) was a protective factor. ConclusionThe incision length of EST is an independent risk factor of duodenal papilla hemorrhage after EPBD. Endoscopic papillary large balloon dilation is a protective factor for postoperative hemorrhage, which can reduce the incidence of bleeding.