Objective：To explore the effect and mechanisms of immune tolerance induced by injecting dendritic cells transfected with Fas ligand gene in allograft recipients. Methods：DCs were prepared from mouse bone marrow and genetically modified by Fas ligand. FasL-DC and LacZ-DC pooled from C57BL／6 donors were iv injected into BALB／c befor transplantation. The propliferative ability of T lymphocytes with the mixed lympiocyte reaction（MLR） was performed to further explore tolerance mechanisms. Results：The Fas ligand gene could be transfected into BMDC and expressed efficiently. The pretreatment of AdFasL modified DC greatly prolonged the survival of cardiac grafts in the recipients，extending survival from 10.0 ± 2.0 days（in LacZ-DC group） and 9.5 ± 1.5 days（in Day-7-DC group） to 21.5 ± 2.5 days. The result of MLR showed that allogeneic T lympiocyte cell proliferation was decreased significantly. Conclusion：The DC transfected with Fas ligand could induce apoptosis of the allogeneic reative T lymphocytes，and pretreatment of AdFasL modified DC could prolonged the survival of cardiac grafts in the recipients.