Abstract： Objective To understand the influence of HBsAg+ pregnant woman on the persistence of hepatitis B surface antibody(HBsAb)of neonates in three years after the first"0,1,6"immunization,and the influences of regular examination every half-year and revaceination in time on maintaining the immune effect. Methods Twenty neonates born from HBsAg-mothers and 24 from HBsAg+ mothers were followed up for 3 years.And children whose HBsAb's titer faded or disappeared(unstable)received recombinate yeast-derived hepatitis B gene vaccine.The proportion of children with unstable HBsAb and the positive rate of HBsAb on 7 month-old and 3 year-old were compared. Results The unstable rate of HBsAb in HBsAg- and HBsAg+ groups were 20.0%(4/20)and 79.2%(19/24),respectively(P<0.05).The rate of revaccination in these two groups were significantly different.The positive rate of HBsAb in 7 month-old children of HBsAg-mothers was 100.0%(20/20)and 62.5%(15/24)in those of the HBsAg+ group(P<0.05).No statistically difference was detected between the two groups when followed up at 3 years of age[85.0%(17/20)vs 91.7%(22/24),P>0.05]. Conclusions HBsAg+ mothers would reduce the stability of HBsAb in their neonates within three years after the first"0,1,6"immunization,but the immune effect of vaccination against hepatitis B can be maintained through regular examination every half or one year and revaccination.