Background and Alms: Postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) is one of the most common and serious complications after endoscopic retrograde cholangiopancreatography (ERCP).This study aims to test the hypothesis that the incidence of PEP declined over time due to improved patient selection and/or endoscopic equipment and endoscopic techniques.Therefore, we compared the incidence and risk factors of PEP between four arbitrary chronologically stratified groups.Methods:A total of 7,168 cases of ERCP procedures were retrospectively analyzed.According to the different developmental stages of ERCP equipment and techniques, cases were divided into four groups.The incidence rates and major risk factors for acute PEP were compared between groups.Results: Among the 7,168 cases, the overall incidence of PEP was 3.70%(265/7,168).When analyzed against each stage of ERCP development, the incidence of PEP was 4.09% (77/1,884) in stage l, 5.79% (86/1,489) in stage Ⅱ, 3.95% (62/1,568) in stage Ⅲ and 1.80% (40/2,227) in stage Ⅳ.By univariate analysis, pancreatic stent placement (OR: 0.300) and use of propofolbalanced anesthesia (OR: 0.632)seem to be protective factors for acute PEP.By multivariate analysis, the following risk factors for PEP could be identified: repeated cannulation (OR: 3.462), pancreatic duct injection (OR: 3.218), balloon di lation of biliary sphincter (OR: 2.847), papillae precut (OR:2.493), nonselective high-pressure injection (OR: 1.428), excessive electrocoagulation incision (OR: 1.263), history of pancreatitis (OR: 3.843) and suspected sphincter of Oddi dysfunction (OR;1.782), Conclusions: Improved technical procedures were associated with a significant reduction in the incidence of PEP.Risks for developing PEP may be minimized by constant improvement in ERCP techniques, such as routine use ofa guidewire, highly selective cannulation, pancreatic stent placement and cautious incision.