Objective To study the effects of 4 1BBL on antitumor immunity induced in vivo by murine 4 1BBL gene transfected hepatocellular carcinoma cell line Hepa1 6. Methods Eukaryotic expression vector pcDNA3 1(+) m4 1BBL was transfered into murine hepatocellular carcinoma cell line Hepa1 6 via lipofectamine method. The transfected cells were selected in RPMI1640 containing G418(400～800 ?g/ml) and termed as Hepa1 6 m4 1BBL.The TCV m4 1BBL was obtained by treating with mitomycin (MMC). Three models (immunological model, early model, and later model) were established for the study of anticancer effects of TCV m4 1BBL. Results The syngeneic mice were completely protected and could survive free from tumor for a long period by inoculation with TCV 4 1BBL. In early models, TCV 4 1BBL showed strong immunotherapy effects( P 0 05). Conclusion The antitumor effect against syngeneic murine hepatocellular carcinoma cell line in vivo is significantly enhanced by the treatment with TCV 4-1BBL.