To evaluate the possible route of intrafamilial transmission among carriers of hepatitis B surface antigen ($HB_sAg$), epidemiologic and serologic data were obtained on 107 household contacts of 35 carriers of HBsAg and on 71 household contacts of 25 controls who were negative for serologic markers of hepatitis B virus. The HBsAg prevalence was 26.5% among the contacts of carriers compared to 0.0% among the contacts of controls. And the combined prevalence for all hepatitis markers was 48.5% among the contacts of carriers compared to 26.0% among the contacts of controls(p<0.05). Especially the offspring of carriers showed significantly higher risk in the combined prevalence for all hepatitis markers (p<0.05). There were no significant relationship between HBV infection and past history like acupuncture, transfusion, operation and tattooed. Factors associated with the risk of intrafamilial transmission of HBV were not found in the sharing of household articles such as razor, towel, drinking glass, nail clippers, toothbrush and tableware.