Abstract: Objective To examine the prevalence of hepatitis B virus(HBV) infection among the populations aged 1-29 years in Liaoning province and to evaluate the effect of immunization strategy of hepatitis B vaccine.Methods With multistage cluster random sampling, 1756 residents aged 1-29 years were selected from 6 counties and districts in Liaoning province.The blood samples were collectd among the residents for the detections of hepatitis B surface antigen(HBsAg), antibody to hepatitis B surface antigen(anti-HBs), and antibody to hepatitis B core antigen(anti-HBc) with enzyme-linked immunosorbent assay(ELISA).Results For all the residents surveyed, the positive rates were 0.68%, 58.94%, and 5.01% and the standardized positive rates were 1.58%, 53.41%, and 9.60% for HBsAg, anti-HBs, and anti-HBc, respectively, and no significant gender differences in the rates were observed.For the residents of different ages, those aged 20-24, 1-4, and 25-29 years had the highest positive rate for HBsAg(3.60%), anti-HBs(71.51%), and anti-HBc(18.64%), respectively.Among the residents, the positive rate of HBsAg and anti-HBc increased generally with the increment of age and there were significant differences in the positive rate of HBsAg, anti-HBs, and anti-HBc between the residents with and without HBV vaccine inoculation history.Conclusion Since hepatitis B vaccine was included into the Expanded Programme on Immunization, the positive rate of HBsAg declined obviously among the residents aged 1-29 years in Liaoning province.