Abstract： Objective To investigate the stent occlusion rate and its risk factor in chronic pancreatitis (CP). Methods From November 2006 to January 2010 a total of 77 pancreatic endoprostheses from 64 patients with CP were tested by simulating the pathophysiologically increased main pancreatic duct (MPD)pressure. The water flow during 15 seconds was recorded 4 times at a pressure of 10 cm water. Kaplan Meier method was used to evaluate the univariate relationship between risk factor and stent occlusion, and Cox regression survival analysis was used to evaluate the multivariate relationship between risk factor and stent occlusion. Results 64 patients with CP were included, with 43 males and 21 females, the mean age was 38 years (range, 4 ～ 80 years). The stents had been placed for a mean of 263 days ( range 26 ～ 759 days).Average stent diameter was 8F (range, 5 ～ 10 F). The overall occlusion rate was 67.5% (52/77), the nonocclusion rates at 90, 180, 360, 540 d were 96. 1% (74/77) , 72.7% (56/77) ,58.4% (45/77) and 35.1% (27/77). In the Cox regression analysis, endoprosthesis diameter ≥8.5F was shown to be the only risk factors for stent occlusion. Conclusions A significant proportion of stents placed after 180 d were not occluded, and were significantly lower than those reported from similar studies overseas. Pancreatic endoprosthesis diameter ≥8. 5F was prone to occlusion.