Abstract: Objective To analyze long-term immune effect of hepatitis B vaccine(HepB)and its influence factors in new borns.Methods With multistage randomized cluster sampling,a cross sectional study was carried out in 1-19 years old persons vaccinated with HepB in Guangzhou.Blood samples of the subjects were collected and then tested for HBsAg and anti-HBs by means of enzyme-linked immunosorbent assay.Results The HBsAg positive rate increased with time after HepB vaccination but the increase was not correlated to the decrease of anti-HBs.Logistic regression analyses showed that booster immunization of HepB(1 year and 6 years after primary immunization)and its dosage were positively associated with anti-HBs.HBsAg was negative in all of the people having been booster immuned at age 1 to 2 years.Conclusion Booster immunization of HepB in children under 2 years old and negative for anti-HBs is an important measure to control the increase of HBsAg positive rate.