Hepatitis B virus (HBV) infection is a global health problem and the clinical outcome of chronic HBV infection depends on the frequency and severity of hepatitis flares in the immune clearance phase. At present, thirty four subgenotypes and ten genotypes (A-J) of HBV are identified and most have specific geographic distributions. The impact of these HBV genotypes on the clinical outcome of chronic HBV infection needs to be further clarified.