The pathologic role of hepatitis B virus (HBV) genotype in Chinese patients with HBV infection is largely unknown. We examined the relationship between HBV genotypes, and hepatitis B e antigen (HBeAg) seroconversion, acute exacerbation, cirrhosis-related complications, and precore/core promoter mutations. Three hundred forty-three HBV patients (288 were asymptomatic, 55 presented with cirrhosis-related complications) were recruited. HBV genotypes and precore/core promoter mutations were determined by line probe assays. Genotypes B and C were the 2 most common genotypes, contributing 28% and 60%, respectively. The median age of HBeAg seroconversion for patients with genotype B was 9 years earlier than patients with genotype C (P =.011). There were no differences in the liver biochemistry, HBV DNA level, and cumulative risk of acute exacerbation (defined as increased alanine aminotransferase level > or =1.5 x upper limit of normal) between patients with genotypes B and C. There was a trend for patients with genotype B to have a higher cumulative rate of HBeAg seroconversion compared with patients with genotype C at the initial follow-up of 6 years (P =.053), but this difference became insignificant during subsequent follow-up. The prevalence of both genotypes was the same in patients with and without cirrhosis-related complications and/or hepatocellular carcinoma. Genotype B was associated with precore mutations (P <.0001), whereas genotype C was associated with core promoter mutations (P <.0001). In conclusion, although patients with genotype B had earlier HBeAg seroconversion, there was no significant reduction in the risk of development of complications. Genotypes B and C are associated with high prevalence of precore and core promoter mutations, respectively.