Abstract: Objective To study the relationship between hepatitis B virus(HBV),DNA content in pregnant mother,mother-fetus cell transportion and HBV in fection in newborn.Methods HBV DNA contents in blood of pregnant women were detected by real-tmie fluorescence quantitative PCR.DNA in mother and infetus was amplified by allele-specific PCR and hem inested PCR.The cell transportion of mother-fetus was determined by detecting GSTM 1 and ACE.HBV DNA in newborns.peripheral blood serum and peripheral blood monouc lear cells(PBMC)was determined by nested PCR.Results The risk of HBV DN A positive in the newborn increased with the increment of serum HBV DNA of the mother(total χ²=13.16,P<0.05,tendency χ²=12.42,P<0.05).But serum HBV DNA content of the mother was not retaled to peripheral blood mononuclear cell(PBMC)HBV DNA positive in the newborn(total χ²=2.41,P>0.05,tendency χ²=0.35,P>0.05)and to the mothe-rfetus cell transportion(total χ²=4.14,P>0.05,tendency χ²=0.001,P>0.05).Mother-fetus cell transportion was related to PBMC HBV DNA positive in the newborn(χ²=10.26,P<0.05),but not related to HBV DNA positive in the new born(χ²=0.49,P>0.05).Conclusion There are associations between HBV DNA content in HBsAg positive mother,mother-fetus cell transportion and HBV infection in newborn.The HBsAg positive mother's HBV DNA content is the risk factor of HBV infection of the newborn and mothe-rfetus cell transportion is the risk factor of PBMC HBV infection of the newborn.