Objective To investigate the effect of tripterygium glycosides on the resistance to immune rejection after allogeneic islet transplantation in mice.Methods Twenty C57BL/6 mice were treated with STZ diabetes mellitus and transplanted the islets from Balb/c mice donor,then recipient mice were randomly divided into two groups:triptolide group and model control group(n=10),and were intraperitoneal injected with tripterygium glycoside solutin and equivalent solvent of 5 mg·kg-1·d-1 for 14 days.Blood glucose and body weight were measured within 4 weeks after transplantation.Two weeks later,two groups of grafted islets were stained by HE staining and immunohistochemical staining,the expression of IL-2 protein were detected by Western blotting.Results The level of blood glucose were decreased to normal in the triptolide group and model control group after islet transplantation,but blood glucose gradually increased in the model control group after two weeks.Compared with the model control group,the inflammatory cells were less infiltrated and the immunohistochemical staining of insulin was deeper in the triptolide group.The expression of IL-2 in the triptolide group was significantly decreased(P<0.05).Conclusion Tripterygium glucoside could significantly decrease the inflammatory cell infiltration and inflammation factor expression in the allogeneic islet recipients to reduce the immune rejection and improve graft survival.