Eight genotypes of hepatitis B virus (HBV) have been detected by sequence divergence > 8% in the entire HBV genome of about 3,200 nucleotides (nt), and designated by capital letters from A to H in the order of documentation. They have distinct geographical distribution and influence the severity of liver disease as well as the response to antiviral therapies. Furthermore, subgenotypes have been reported for genotypes A (HBV/A), B and C, and named Aa/A1 (Asian/African type) and Ae/A2 (European type), Bj/B (Japanese type) and Ba/B2 (Asian type), and Cs/C1 (Southeast Asian type) and Ce/C2 (East Asian type). There have been increasing lines of evidence that subgenotypes of A and B influence the replication of HBV and are clinically relevant. In Japan, mass vaccination has not been performed because of the extremely high efficacy of immunoprophylaxis on babies born to carrier mothers; it has decreased the persistent HBV carrier state from 1.4% to 0.03%. However, HBV/Ae of the European type has increased in young male adults by sexual transmission because the foreign genotypes have been imported from sexual workers where the genotypes are prevalent. Here, we summarize the clinical manifestations of HBV genotypes.