Objective To investigate the expression status of HBV X gene,TGF-alpha,c-myc,beta-catenin and 249 codon mutation of p53 in HCC cell lines for exploring their possible role in hepatocarcinogenesis in area of prevalence.Methods Cell lines 7701 and 7703 derived from Qidong HCC were used.HBV X gene in cell DNA was identified by PCR and sequencing.X gene expression was assessed by RT-PCR and Western Blot.249 codon mutation status of p53 gene was analyzed by PCR-RFLP.The expression level of TGF-alpha,c-myc and beta-catenin was determined by immuno-cytochemistry.Results Presence of partical HBV X gene sequence was identified by PCR and confirmed by DNA sequencing in both cell lines.This was consistent with negative findings at transcriptional and translational level by RT-PCR and Western Blot.130、131 codon variation of X gene was found in both cell line.PCR-RFLP demonstrated that the 249 codon of p53 gene was of wild type.Strong expression of TGF-alpha,c-myc,beta-catenin protein was shown in both cell lines by immunocytochemistry.Conclusion In both cell lines,HBV X gene sequences are identified as a genetic marker of previous HBV exposure.The X gene is not expressed,possibly as a result of truncation near 3′end.The 249 codon of p53 gene is of wild type.Strong expression of TGF-alpha,c-myc and beta-catenin suggests their possible role in hepatocarcinogenesis.