Abstract: Objective To construct a model in vitro of HBV infection of human trophob last in mother-to-child transmission during pregnancy through studying the possibility of human placental trophoblast Bewocell line infection of hepatitis Bvirus(HBV).Methods The human trophoblast Bewocell line were co-cultured with HBVDNA positive sera.HBVDNA copies in Bewoculture supernatant was measured by fluorescence quantitaive PCR.Immunoh is tochemistry ABC was conducted to detect expression of HBsAg in Bewo cell climings lide.Results HBVDNA was successfully detected in Bewo culture supernatant after co-culturing for 24 and 48 hours with HBVDNA positive sera.Expression of HBsAg was successfully detected in Bewocells.Co-culturing with HBVDNA positive sera had no obvious impact on Bewocell morphology.Conclusion The human trop hoblast Bewo cell line can be infected by HBV through co-culture with HBVDNA positive sera.The model can be used to study the mechanisms of HBV infection in placenta.