Abstract: H22 cells, a hepatocellular carcinoma cell line of BALB/c mice originally, were transfected with human GM - CSF via recombinant adenoviral and then irradiated byo'Coy ray. Bearing mice were treated by above tumor vaccine. We determined the lymphocytes subsets in peripheral blood of bearingmice by using Flow Cytometer (FCM). We also observed the survival stage of ab0ve animals. Our resultsfollowed that treatment with GM - CSF - trans fected, irradiated H22 cells not only increased the percentageof CD + T - lymphocytes in peripheral blood, but also significantly prolonged survivals of tumor bearingmice. The result suggests that irradiated, GM - CSF - trans fected tumor cells could induce effective antitumor immunity, which indicates the feasibility of cancer gene therapy.