Objective To investigate the efficacy of telbivudine blocking the spread of hepatitis B virus in intrauterine. Methods Collecting 64 cases of pregnant women who receive treatment in Hangzhou Sixth People's hospital between November 2007-June 2009,which are divided into control group (36 cases)and treatment group (28 eases). Two groups of pregnant women intramuscular HBIG 200IU each one times during pregnancy 28, 32 and 36 weeks. Pregnant women of treatment simultaneously oral telbivudine tabels,600 mg/d. To observe the HBV DNA load and HBsAg levels in newborns of two groups. Results HBsAgpositive rate is 30.56% (11/36) in newborns of the treatment group, which is 7. 14% (2/28) in control group. The difference is statistically significant between two groups ( χ2 = 3. 985, P = 0. 046 ). HBV DNA positive rate is 1 16.67% (6/36) in newborns of control group, which is 0 in treatment group. The difference is statistically significant between two groups ( P ＜ 0.05 ). All pregnant women and newborns do not appear adverse reactions during the treatment. Conclusion HBV blocking rate of treatment group is significantly higher than control group. The results suggest that telbivudine can reduce the risk of HBV vertical transmission to a certain extent.