Chinese same-sex twins were recruited in order to study the distribution of different markers of hepatitis B virus (HBV) infection, including HBV surface antigen (HBsAg), antibody to HBV core antigen (anti-HBc), antibody to HBsAg (anti-HBs), HBV e antigen (HBeAg) and antibody to HBeAg (Anti-HBe), as well as to compare the concordance of these markers in pair-wise fashion among monozygotic (MZ) and dizygotic (DZ) twins and singleton controls. A total of 289 pairs of MZ twins, 102 pairs of DZ twins and 375 pairs of age-sex-matched singleton controls were studied. More than 50 percent of the members of each group (64.71% of MZ twins, 51.96% of DZ twins and 62.13% of controls) were found to be infected with HBV. In general, the patterns of the response to HBV infection in the 3 groups were similarly distributed. 20.17% of the members of the 3 groups (21.45% of MZ twins, 14.22% of DZ twins, and 20.80% of controls) were HBsAg carriers. Among the HBsAg carriers, 49.19% (44.35% of MZ twins, 34.48% of DZ twins and 55.77% of controls) were HBeAg carriers. No significant difference in the concordance of HBV infection was observed in the MZ and DZ twins. However, highly significant differences were noted between MZ twins and controls, and between DZ twins and controls. Highly significant differences were also observed in the concordance of carrier status between MZ and DZ twins and between MZ twins and controls, but not between DZ and controls. As for the other HBV markers, no significant differences were observed. It is concluded that the genetic influence in response to HBV infection markers is not well-characterized and requires further study.