Objective To establish immortalized human hepatocyte lines for studies of bioartificial liver,hepatocyte transplantation,and drug metabolism in vitro.Methods Primary human hepatocytes were isolated by 4-step perfusion technique with collagenase and transfected with recombinant retrovirus containing Simian virus 40 large T antigen(SV40 LT).Subsequently,immortalized human hepatocytes were evaluated by analysis of gene expression and functional characteristics in vitro.Results Two immortalized human hepatocyte lines,HepLi2 and HepLi3,were obtained after primary human hepatocytes being infected by SV40 LT containing recombinant retrovirus for 3-4 weeks.The immortalized human hepatocytes showed classical appearance of hepatocyte observed by phase contrast microscope.The protein expression of SV40 LT in HepLi2 and HepLi3 cells were detected by Western blotting.The mRNA expressions of albumin(Alb),glutathione S-transferase(GST-p),human blood coagulation factor X(HBCF-X)and β-actin in HepLi2 and HepLi3 cells were detected by reverse transcription polymerase chain reaction(RT-PCR),and the mRNA expressions of cytochrome(CY)450 subtypes(CYP3A5,CYP2E1,CYP2C8-19 and CYP3A4)in HepLi2 and HepLi3 cells were also observed by RT-PCR.Levels of alanine transaminase (ALT),lactate dehydrogenase(LDH)and Alb were detected in the supernatant of immortalized human hepatoeyte culture.Conclusions The immortalized human hepatocyte lines have the biological characteristics of primary human hepatocytes and have the CYP450 functions of hepatocytes,which may be heIDful for the studies of bioartificial liver,heoatocvte transplantation and drug metabolism in vitro.