Abstract： Objective To explore the expression level of Tim-3,the marker of activated T_H 1 cells.in T lymphocytes in different sites from recipients with acute rejection.Methods The model of cervical heterotopic heart transplantation was established in mice Two groups were get up:the isograft group(C57BL/6→C57BL/6) and the allograft group (Balb/c→C57BL/6).Lymphocytes were isolated from peripheral blood,spleens,draining lymph nodes and grafts 3 or 6 days after transplantation.The expression of TIM-3 in CD4~+ and CD8~+ T subsets was detected by flow cytometry.Results There was no significant difference in Tim-3~+/CD4~+ and Tim-3~+/CD8~+ ratio in peripheral blood or spleens between two groups.As compared with the isograft group,the proportion of Tirn-3~+/CD4~+ cells was slightly elevated in draining lymph node(P<0.05),but the percentage of Tim-3~+/CD4~+ cells had no significant change between 3 days and 6 days in the allograft group(P>0.05).The expression of Tim-3 in CD4~+ and CD8~+ of graft infiltrating T cells was obviously increased in allograft group(P<0.01),and it was significantly (P<0.01) up-regulated on the 6th day as compared with that on the 3rd day.Conclusion The dynamic changes of Tim-3 expression in T lymphocytes in draining lymph node and graft were correlated with the progresston oi acute rejection in mice.