BACKGROUND:?Recurrence of hepatitis B virus (HBV) after orthotopic liver transplantation is very common in the absence of adequate prophylaxis and is often associated with poor prognosis because of the development of cirrhosis, ifbrosing cholestatic hepatitis, or fulminant hepatitis. Therefore it is important to study the prevention of HBV reinfection after liver transplantation. METHODS:Recombinant Fab (rFab) was constructed to evaluate gene therapy for post-transplantation HBV re-infection. Hepatocytes were divided into three groups:HBV-infection, rFab-blocked HBV-infection, and control. The inhibition of HBsAg adsorption test, the micro-cytotoxicity assay, and the blockade test of HBV infection were carried out. The HBsAg adsorption rate, the hepatocyte death rate and the HBV infection rate were statistically analyzed. RESULTS:?The HBsAg adsorption rate blocked by rFab in the HBsAg adsorption test was 0.3%. The hepatocyte death rate was 98.8% induced by rFab in the micro-cytotoxicity assay, 1.3%in the rFab-blocked HBV-infected group and 77%in the HBV-infected group in the blockade test of HBV. CONCLUSIONS:?We found that rFab effectively blocked HBV infection in human hepatocytes. This provides an attractive alternative for hepatitis B prophylaxis.