Abstract: Background Allogeneic skin graft is an important treatment in the early stage of large area burn. Bone marrow mesenchymal stem cells (BMSCs) can reduce transplant rejection and may provide new therapeutic ideas for the treatment of allogeneic skin graft rejection in burn patients. Objective To investigate the feasibility of infusing donor-derived BMSCs into recipient mice with skin allograft transplantation to inhibit allograft rejection.Methods Mouse BMSCs were isolated and cultured in vitro to verify the expression of surface markers. The ability of BMSCs to inhibit the proliferation of T lymphocytes was detected by CCK8 and CTV assays. C57BL/6J mice were randomly divided into Blank group, Autograft group, Control group (allograft) and BMSCs group (allograft +BMSCs) to verify the ability of BMSCs to inhibit allogeneic allograft rejection. The survival time of skin grafts was observed, and the proportion of regulatory T cells in lymph nodes and spleens was detected. Results In this study, BMSCs obtained by primary culture showed low expression of CD45 and CD34, and high expression of CD105 and CD106, which was consistent with the marker expression of BMSCs. In the T cell proliferation suppression culture system, mesenchymal stem cells can effectively suppressive T cell proliferation, and the higher the proportion of mesenchymal stem cells, the stronger the inhibitory effect on T cell proliferation. Mice injected with mesenchymal stem cells showed longer skin graft survival than mice transplanted with allogeneic skin grafts alone. Skin allograft recipients injected with mesenchymal stem cells showed higher regulatory T cells proportion in the lymph nodes and spleens after surgery than mice in the skin graft alone group.Conclusion BMSCs have been successfully isolated and cultured in this study, the results demonstrated that BMSCs could effectively inhibit the proliferation of T lymphocytes in vitro, prolong the survival time of grafts, and increase the proportion of regulatory T cells in lymph nodes and spleens after infusion into mice.