Objective：To investigate the regulatory effect of hepatitis B virus （HBV） on the expression of Pahsa and to discuss its mechanism. Methods：RT-PCR and Western blot were performed to check Pasha expression in HepG2 and HepG2-H7 cell lines. Pasha promoter luciferase reporter plasmid，pGL3-Pasha-P，was constructed and transiently transfected into HepG2 and HepG2-H7 cells to anlyze the activity of Pasha promoter. Then HepG2 cells were transiently cotransfected with 0.5 μg of pGL3-Pasha-P and HBx，HBs，HBp，HBc expression plasmids，respectively and the luciferase activity was detected. Results：The results of RT-PCR and Western blot showed that the expressions of Pasha in HepG2-H7 cells were lower than those in HepG2 cells. The luciferase activity assay of Pasha promoter demonstrated that HBV could suppress Pasha promoter activity and HBx and HBs proteins may play impor－tant roles in this process. Conclusion：HBV can down-regulate Pasha expression in HepG2-H7 cells through inhibiting its promoter activity.