【Objective】 To investigate the effects of granulocyte-macrophage colony stimulating factor(GM-CSF) on intrauterine hepatitis B virus (HBV) infected infants and the serum Thl/Th2 balance. 【Methods】 Forty intrauterine infected infants entered the study.They were randomized into two groups.Twenty babies were assigned to GM-CSF group and received combined therapy with 10 μg of rHBvac and 200 U HBIG injected intramuscularly at different sites,10 μg/kg of GM-CSF intradermally after three days at receiving rHBvac the same point.Twenty babies were assigned to control group and receiving 200 U HBIG and 10 μg intramuscular rHBvac injections at different sites.One year after birth,the post-treatment serum samples were collected to test HBV-DNA quantification and other HBV serological markers with the baseline samples at the same time.Levels of interferon-gamma (IFN-γ) and interleukin (IL)-4 in blood serum in spontaneous and superuatant were measured by enzyme-linked immunosorbent assay(ELISA). 【Results】 All subjects completed the three -dose schedule,no adverse events were reported in either group.After the treatment,5 children became HBsAg and HBV DNA negative in GM-CSF group,however the difference did not reach to a significant level;One children became HBsAg and HBV DNA negative in control group.The IFN-γ levels of GM-CSF group were significantly higher than those of control group(P<0.01).There was no significant diference in IL-4 levels among the two groups (P>0.05). 【Conclusion】 Combined GM-CSF,rHBvac and HBIG therapy have some use in intrauterine infected infants who are not protected by immunoprophylaxis.