Objective To investigate apoptosis of HepG2 ceils after transfecfion with LIGHT gene and interferon-γ. Methods LIGHT gene and interferon-γ were transfected into HepG2 cells by liposome mediated method. The HepG2 cells were divided into group A (transfected with LIGHT gene or interferon-γ), group B (transfeeted with LIGHT gene and interferon-γ) and group C (non-transfection group). The apoptosis rate of the HepG2 cells and the expression of Bcl-2 and Caspase-8 were detected 12, 24, 48 hours after transfeetion. Results (1) The apoptosis rates of HepG2 cells at hour 12, 24 and 48 after transfeetion were 18.8% ± 3.5%, 25.7%± 2.8% and 36.4% ±3.6% in group A, 23.8% ±2.4%, 31.1% ±2.1% and42.5% ±4.5% in group B, and 8.7% ± 2.1%, 9.3% ± 1.6% and 10.9% ± 1.2% in group C. There was a significant difference in apoptosis rate among the 3 groups (F = 15.69, 53.33, 48.28, P < 0.01). (2) The expression of Bcl-2 in HepG2 cells at hour 12, 24 and 48 after transfection was 16.4% ± 5.0%, 13.4% ± 3.5% and 8.6% ± 2.3% in group A, 14.7%±3.8%, 9.1% ±2.0% and 4.6% ±2.0% in group B, and 25.3% ±6. 3%, 19.8% ±4.4% and 10.1% ±3.8% in group C. There was a significant difference in the expression of Bcl-2 among the 3 groups (F = 6.19, 12.29, 5.81, P <0.05). (3) The expression of Caspase-8 at hour 12, 24 and48 after transfection were 19.3% ±2.4%, 27.2% ±1.9% and 33.7% ±3.0% in group A, 22.7% ±2.2%, 30.9% ±3.1% and 38.2% ±3.2% in group B, and 1.2% ±0.8%, 1.8% ±0.6% and 3.2% ±1.5% in group C. There was a significant difference in the expression of Caspase-8 among the 3 groups (F =71.54, 112. 78, I01.61, P < 0.01). Condusions LIGHT gene can signiticanfly promote cell apoptosis through regulating the expression of Bcl-2 and Caspase-8. Interferon-γ enhanced the effect of LIGHT gene on the apoptosis of HepG2 cells.