Abstract: To investigate the roles of pancreatic and peripancreatic tissues in acute pancreatitis,the rat model of acute biliary pancreatitis was established by retrograde injection of sodium taurocholate into the pancreatocholangitic duct and the primary and secondary lesions as well as pancreatic pathologic findings were observed. 1. Gross pathologic findings: at the same interval after model establishment, differences between the groups were very significant （P＜0.01）. A positive correlation existed between the severity of pancreatic and peripancreatio pathological changes （P＜0.01）. 2. Microscopic pathologic findings：at 6 hours，the necrosis of interstitial hemorrhage and fat differences between the groups was significant （P＜0.05），and the other lesions were significantly different （P＜0.01）. 3. Exceptional pathologic findings：in two cases, mild pancreatic edema or necrosis with extensive infiltration in the retroperitoneal space. In three cases, severe pancreatitc edema or hemorrhagic necrosis with localized retroperitoneal infiltration. In five cases, hemorrhagic necrotizing model with severe lesions of splenic hilum. Under comparable conditions of model preparation, the severity of primary lesions is parallel to that of the second ary lesions. The discrepancy of the local lesions may be related to the differences of local tissue structures.

Key words: Pancreatitis, Animal models, Rat, Pathology