Abstract: Objective To elucidate the status quo of hepatitis B virus (HBV) in vertical transmission in Baoshan region in Shanghai and to provide the basis for prenatal and postnatal health promotion.Methods Pregnant women with Hepatitis B surface antigen (HBsAg) positive/Hepatitis B e antigen (HBeAg) positive were enrolled in this study from 632 pregnant women for delivery in our hospital during September 2010 and June 2011. Umbilical cord blood from newborns was collected and measured for HBV serological markers.Results In the total of 632 pregnant women, 236(37.34%) were HBsAg positive and/or HBeAg-positive HBV-positive patients，of whom 93(39.41%) were HBsAg positive. The umbilical cord blood of their newborns showed that 56 cases(23.73%) were HBV-positive, and 8(3.38%) infants were HBsAg positive. The HBV-positive newborns included 30 males, accounting for 22.90% of the total males, and 26 females, accounting for 24.76% of the total female infants. In 143 cesarean section newborns, the umbilical cord blood collected showed that HBV markers were positive in 32 cases, the positivity rate being 22.38%. In 93 cases of vaginal delivery, the umbilical cord blood collected showed that HBV were positive in 24 cases, the positivity rate being 25.80%.Conclusion The placenta may prevent part of HBV virus from entering the fetus. Newborn HBV-positivity rate is not related to the mode of delivery or neonatal sex.