To investigate the effects of dendritic cells on T lymphocyte proliferation and apoptosis, providing an in vitro model of clinical transplant immunological tolerance. After mature dendritic cells ( mDCs) from peripheral blood of healthy adults was successfully transfected with human FasL gene, mDCs were analyzed for the expression of cell surface molecules, antigen presenting function and their apoptosis. Effects of mDCs on T lymphocyte proliferation and apoptosis were further detected based on co-culture of mDCs and T lymphocytes. The results show that, FasL did not significantly change the expression level of mDC's surface molecules CD40, CD80, CD86 and HLA-DR; FasL did not induce apoptosis of mDC. No effects on the antigen presenting function of mDC were observed as well. The mDC transfected with FasL decreased stimulation index and increased apoptosis of allogeneic T-lymphocyte significantly. So that, human mDCs transfected with FasL may regulate T lymphocyte proliferation and apoptosis without alteration of cell surface molecules and antigen presentation characteristics on human mDC.