Abstract: Objective To evaluate epidemic characteristics and risk factors of hepatitis B(HB)after the HBV integrated in to the Expanded Programme on Immunization(EPI)in Jiangsu province.Methods Totally 3 906 participant were included for the field and sero-epidemiology survey.Results The positive rate of HB sA g,anti-HBs,anti-HBc and the infection rate of HBV among the partic ipants were 4.99%,58.70%,25.91%,and 25.93%,respectively.The vaccination rate was 96.99%in people <15 years old and the in-time rate of the first vaccination was 70.75%.Compared with other age groups,the positive rate of HBsAg,anti-HBs and the infection rate of HBV in people <15 years old were lower,but the positive rate of anti-HBs was higher.The positive rate of HbsAg in the urban and rural subjects were 5.19% and 4.80%,respectively.There were 41.67% of the couples being both HbsAg positive among the participants.Conclusion After the HB vaccine in troduced in to EPI,both the infection rate of HBV and the positive rate of HbsAg declined obviously,especially for the people <15 years old.The peak of infection was lagged.The first dose timely vaccination rate of hep a titis Bvaccine is still low.