The epidemiology of chronic hepatitis B infection worldwide shows that China has a high prevalence of hepatitis B infection and belongs to the high prevalence zone of hepatitis B. The rate of hepatitis B surface antigen (HBsAg) positivity is >8% compared to less than 2% in the United States. Seroepidemiological studies of hepatitis B virus done in China in the early and mid-1990s showed that the HBsAg positivity rate was 9.75% (4.49%-17.85%), higher in men (11.33%) than in women (8.23%), higher in rural areas (10.44%) than in non-rural areas (8.44%), higher in the south than in the north, higher in rural than in urban areas, higher in the east coast than in the west. Among the HBsAg-positive population, 31.94% were positive for hepatitis B e antigen (HBeAg), 49.81% were positive for hepatitis B core antibody (anti-HBc or HBcAb), and 27.42% were positive for hepatitis B surface antibody (anti-HBs or HBsAb). Therefore, hepatitis B has become a very serious public health problem and should be taken seriously to enhance prevention and reduce morbidity.