Hepatitis B surface antibody is not permanent in the body, with the prolongation of time and the decline of body immunity, the number of hepatitis B surface antibody will gradually decrease or even disappear. Hepatitis B surface antibody is produced after vaccination against hepatitis B or infection with HBV. Surface antigen stimulates the body’s immune system to produce specific immunoglobulin, which is surface antibody. This globulin is the surface antibody, which can bind specifically to the surface antigen to remove the hepatitis B virus and protect the body from further attack by the hepatitis B virus. Hepatitis B surface antibody is a kind of protective antibody. If it is produced through hepatitis B vaccination, it means that the vaccination is successful, and if it is produced after recovering from HBV infection, it means that chronic hepatitis B or acute hepatitis B has been cured. The higher the amount of hepatitis B surface antibody, the stronger the protective effect on the human body, and the antibody usually lasts for at least 12 years, or even longer. Surface antibody monitoring or booster immunization is not necessary for the general population, but it can be done for high-risk groups. If the amount of surface antibody is less than 10 IU/mL, a booster shot of hepatitis B vaccine can be given.