Objective To design and create a C/S-J type of biliary self-releasing stent,and to study its safety and efficacy in preventing post-ERCP complications.Methods 118 patients with common bile duct stones treated in our hospital were enrolled into this study from October 2013 to May 2015.These patients were randomly divided into two groups:the experimental group who underwent ERCP + EST + C/S-J type of self-releasing biliary stent drainage,while the control group underwent ERCP + EST + ENBD.The incidences of post-ERCP acute pancreatitis (PEP) and cholangitis in the two groups and the time the self-releasing stent was dislodged from the biliary system in the experimental group were recorded.Results The incidence of PEP was 6.4％ (5/78) and 7.5％ (3/40) in the experimental and the control group,respectively (P ＞ 0.05).There were no patients who developed postoperative acute cholangitis in the two groups.The stents were dislodged from the biliary system on the first day after the procedure in 2 patients in the experimental group without any complications.One stent failed in self-releasing but was removed successfully with endoscopy 3 months later.In the other 75 patients,the stents were successfully dislodged and were excreted outside the patient's body through the intestinal tract (mean 11.4,range 9 ～ 14) days,without any complications.Conclusion The C/S-J type of biliary self-releasing stents is safe and efficacious in preventing post-ERCP pancreatitis and cholangitis.