To evaluate the effects of different pressure and duration of autologous bile perfusion into dog’s pancreatic duct on the severity of induced acute pancreatitis. Thirty mongrel dogs were divided into five groups, with each group consisting of six dogs. Histological changes of pancreas were observed. Results: Histological changes of pancreas were correlated with the pressure and duration of autologous bile perfusion into pancreatic duct. It was easier to produce acute hemorrhagic necrotizing pancreatitis in the groups with a higher pressure and a longer duration of perfusion than in the groups with a lower pressure and a shorter duration. The results indicated that there was a significant effect of higher pressure and longer duration bile perfusion into pancreatic duct on the severity of induced acute pancreatitis.