Abstract: Objective To examine the familial aggregation of hepatitis B virus(HBV) infection and its influence factors in minority areas of Guizhou province and to provide evidences for the prevention and control of HBV infection.Methods By using multistage cluster random sampling,1 629 permanent residents were recruited from eight villages of two counties in minority areas of Guizhou province and surveyed with a questionnaire and HBV serological indexe detection.Results Among the residents,the overall HBV infection rate was 50.6%;the positive rate of hepatitis B surface antigen(HBsAg) was 8.3%;and the familial aggregation rate of HBV infection was 19.58%.The results of binomial distribution fitting revealed a trend of familial aggregation in HBV infection among the residents with the families having more than 2 members(χ²=14.409,P<0.05).Among the residents from the families with HBV infection aggregation,no significant difference in the HBV infection rate was observed between the family members grouped by various family relations(53.3% for couple,50.0% for father-child,48.4% for mother-child,44.4% for sibling,and 53.4% for grandparent-grandchild relationship,respectively(χ²=2.598,P=0.627).The results of multivariate non-conditional logistic regression analysis showed that with a HBsAg positive family member,big family size,and history of migrant working were risk factors of HBV infection familial aggregation in minority areas,whereas,HBV vaccination history and with higher total family income in previous year were protective factors.Conclusion Familial aggregation of HBV infection exists in minority areas of Guizhou province and the aggregation is influenced by HBsAg positivity of family member,status of HBV vaccination,total family income in previous one year,family size,ant the history of migrant working.