AIM To observe the effect of recombinant tumor necrosis factor α (rHTNFα) and mutant interleukin 2(IL-2) on the hepatocarcinoma cell line in vitro. METHODS The hepatocarcinoma cell line (H7402) was used as a cell culture system in vitro. H7402 was cultured with different concentrations of rHTNFα and/or mutatant IL-2. The cytotoxity was measured by short term MTT method. RESULTS The inhibitory effect on H7402 became stronger with the increase of the concentration of rHTNFα (r=0.909，P＜0.05). Mutatant IL-2 had no direct inhibitory effect, but could enhance the effect of rHTNF α in inhibiting H7402 cell line. The concentration of both rHTNF α and mutant IL-2 affected this enhancement: 2.5×10.3U/ml of mutant IL-2 could increase cytotxity of rHTNFα (1000 U/ml) to H7402 effectively. When rHTNFαreached 5×10 4U/ml, the enhancement appeared only when the concentration of mutant IL-2 was at 2×10 4U/ml. If the dose of rHTNFαwas at 8×104 U/ml, the inhibitory effect did not rise significantly until mutant IL-2 was at 4×10 4U/ml. CONCLUSION rHTNFα combined with mutatant IL-2 in low concentration can yield good inhibitory effect on hepatocarcinoma.