Abstract: Objective To understand TLR3's expression on the PBMC and explore the relationship between TLR3 and PBMC HBV intrauterine infection.Methods 228 HBSAg positive pregnancy women were followed-up to delivery by nest case-control study,HBsAg and TLR3 on HBsAg positive pregnancy women and PBMC smears were detected by immunoflu orescence double staining.Results 64 PBMC smears were detected.PBMC HBsAg positive were found from 228 HBsAg positive pregnancy women in serum and the positive rate' was 28.07%;161 PBMC smears were detected by TLR3 positive and the positive rate was 70.61%(161/228),TLR3's expression was statistical sig nificance in PBMC HBV infection group compared with non-infection group(P<0.0001);35 PBMC smears were detected HBsAg positive from 228 HBsAg positive(in serum)pregnancy women's newborn infants and the positive rate was 15.35%;the expression of TLR3 on pregnancy women's PBMC were relative with PBMC HBV intrauterine infection of new born infants(P<0.0001).Conclusion TLR3 probably is a protective factor for PBMC HBV infection of HBsAg positive(in serum)pregnancy women(OR=0.181,OR95%CI=0.091-0.340),and is also a protective factor for PBMC HBV intrauterine infection of newborn infants(OR=0.279,0R95%CI=0.133-0.585).