Objective To investigate the role of pancreatic β cell on pancreatic regeneration following experimental acute pancreatitis.Methods Eighty-seven SD male rats were randomly divided into four groups:control group ( n =15 ),STZ group ( n =24),L-Arg group ( n =24 ),STZ + Arg group ( n =24).60 mg/kg of STZ was administrated by intraperitoneal injection to induce the diabetes model.2.5 g/kg body weight of LArg was administrated by intraperitoneal injection to induce the acute pancreatitis model.The rats were sacrificed 1,3,5,7 d later and the serum levels of amylase and glucose were measured.Relative pancreatic weight (pancreatic weight/body weight) were measured.Pancreatic tissue underwent routine pathologic examination,and the percentage of area of necrosis and tissue transformation was calculated.The expression of Reg4 and insulin was performed by immunofluorescence.Results Serum level of glucose significantly increased after STZ injection.After L-Arg injection,serum level of amylase significantly increased,and there was pancreatic tissue edema,necrosis,infiltration of inflammatory cells,which suggested the successful model induction.The percentage of area of necrosis in STZ + L-Arg group was (71.6 ± 6.0) ％ at the 3rd day,which were significantly higher than (42.3 ± 4.0 ) ％ in L-Arg group; the percentage of area of transformation was (45.6 ± 5.4) ％,which were significantly lower than (78.5 ± 6.4) ％ in L-Arg group.Expression of Reg4 in pancreatic islets of STZ + L-Arg group was significantly lower than those in L-Arg group.Conclusions STZ impairs pancreatic β cells,aggravates pancreatic damage following L-arginine induced pancreatitis and inhibits pancreatic regeneration.