〔Abstract〕 Objective To explore effects of interleukin-2(IL-2) and IL-2 receptor(IL-2 R) on Fas/FasL expression and T cell apoptosis in renal transplantation immune tolerance induced by bone marrow mesenchymal stem cells(MSCs). Methods Thirty BALB/c mice with immunodeficiency and thirty C57 BL/6 mice were randomly divided into 3 groups(control group, transplant group, IL-2 group), 10 the former mice and 10 the latter mice in each group. In transplant group, kidneys of C57 BL/6 mice were transplanted into BALB/c mice. After 24 h, normal MSCs were intravenously injected into transplant receptors. In IL-2 group, IL-2 mRNA and target gene were introduced into MSCs, and then they were intravenously injected into transplant receptors. The expression of IL-2 mRNA and IL-2 R mRNA in mice was detected. The levels of IL-2, transforming growth factor β1(TGF-β1), soluble apoptosis-related factors(sFas) and their ligands(sFasL) in mice blood were detected by ELISA. Western blot was applied to detect the expression of JAK, STAT3 and p-STAT3 in renal tubular epithelial cells. Results Compared with control group, the expression of IL-2 mRNA and IL-2 R mRNA, levels of serum TGF-β1, sFas and sFasL, and the expression of JAK and p-STAT3 proteins in renal tubular epithelial cells were increased in transplant group(P<0.05). There was no statistical difference in STAT3 in renal tubular epithelial cells(P>0.05). Compared with transplant group, the expression of IL-2 mRNA and IL-2 R mRNA, levels of serum TGF-β1, sFas and sFasL, and the expression of JAK and p-STAT3 proteins in renal tubular epithelial cells were increased in in IL-2 group(P<0.05). There was no statistical difference in STAT3 in renal tubular epithelial cells(P>0.05). Conclusion Il-2 can enhance rejection to transplanted kidney by promoting the expression of Fas/FasL and mediating apoptosis of T cells.