Abstract: AIM: To explore the effect of immune tolerance in rat cardiac allograft induced by donor splenocytes or bone marrow combined with asarinin 7 days before surgery. METHODS: Asarinin was extracted from herba asari. Eighty Sprague Dawley rats (recipients) were randomly divided into five groups and were treated 7 days preoperatively: control group (no treatment); cyclosporin group, asarinin group, splenocyte-inducing group (splenocytes and asarinin), and bone marrow-inducing group (bone marrow and asarinin). Eight rats in each group were sacrificed and the other eight rats were left in order to observe survival time. Mixed lymphocyte reaction (MLR) between donor and recipient was examined with MTT and levels of serum IL-2, IFN-γ, IL-4 and IL-10 were detected with ELISA 7 days postoperatively (n=8). RESULTS: Allograft survival time was prolonged in cyclosporin group, asarinin group, splenocyte-inducing group and bone marrow-inducing group (P<0.01). Lymphocyte proliferation was alleviated in asarinin group, splenocyte-inducing group and bone marrow-inducing group compared with control group (P<0.01). Level of IL-4 and IL-10 significantly increased in splenocyte-inducing group and bone marrow-inducing group compared with the cyclosporin group (P<0.01). CONCLUSION: Immune tolerance, which is specific to the donor, can be induced by donor splenocytes and bone marrow cells. Immune tolerance induced by donor rat splenocytes or bone marrow cells combined with asarinin prolongs survival time of allografts and protects the transplanted organ.