Objective To investigate the effects of mesenchymal stem cells(MSCs) derived from recipients’ bone marrow on the acute rejection in rat models of cardiac transplantation and to study the possible underlying mechanisms. Methods Twenty Wistar rats bearing transplanted heart from Lewis rats were divided randomly into control group and MSCs treatment group, with 10 in each group. The rats in control group received 3ml 0.9%NaCl solution injection through tail vein at 24h after heart transplantation. The rats in treatment group received 2×106 MSCs suspended in 3ml 0.9%NaCl solution instead. One week after transplantation, 4 rats selected randomly from each group were sacrificed for detection of interleukin(IL)-2 and IL-10 levels in inferior canal vein by ELISA and immunohistolochemical examination. The left 6 rats in each group were used for determination of the grafts survival time. Results The survival time of allografts was (7.2±1.3)d in control group and (14.8±2.9)d in MSCs treatment group respectively(P＜0.01). Serum IL-2 concentration was (233.99±30.19) ng/L in control group and (249.11±20.34) ng/L in MSCs treatment group(P＞0.1). Serum IL-10 concentration was (81.44±11.01) ng/L in control group and (158.39±18.70) ng/L in MSCs treatment group(P＜0.01). In control group, there was 1 case with pathological grade 3B and 3 cases with grade 4. In MSCs group, there was 1 case with grade 2, 2 cases with grade 3A, and 1 case with grade 3B. MSCs treatment group had comparatively lower pathological grade than control group. Conclusion Intravenous infusion of MSCs derived from recipients could prolong the survival time of transplanted heart and reduce the acute rejection.