Positive hepatitis B surface antibody indicates that the body is immune to the hepatitis B virus and is a protective antibody, which is normal and has no symptoms. Hepatitis B surface antibody positivity is commonly seen after acute hepatitis B has been cured, and also after hepatitis B vaccination. Some adults may have a hidden infection after exposure to the hepatitis B virus without symptoms of acute or chronic hepatitis, and may be positive for hepatitis B surface antibodies. There are also a small number of people who recover after an acute episode of the hepatitis B virus, in which the hepatitis B virus is completely cleared by the body and subsequently hepatitis B surface antibodies are produced in the body. People who are not infected can also produce positive hepatitis B surface antibodies through hepatitis B vaccination. At present, our country has included the hepatitis B vaccine in the child immunization program, and newborns are routinely vaccinated against hepatitis B at 0, 1, and 6 months of age. The higher the titer of hepatitis B surface antibody, the stronger the body’s immunity and protection against hepatitis B virus infection. This titer may gradually decrease with age. Adults, especially those with a family history of hepatitis B, should have their hepatitis B surface antibodies tested regularly. If the antibodies are gone, they should be promptly immunized with the hepatitis B vaccine.