Hepatitis B virus surface antibody is positive, you can consider that you have been infected with hepatitis B virus or vaccinated with hepatitis B vaccine in the past. 1. Previous infection: If you have been infected with hepatitis B virus in the past and have been cured, the presence of hepatitis B virus antibody in your body is a normal immune phenomenon. The immune cells of the body will carry out targeted immune response to the invading hepatitis B virus, thus stimulating the body to produce corresponding antibodies, which can effectively fight infection. 2. Vaccination: For people who have never been infected with hepatitis B virus, positive surface antibody is generally considered to have been vaccinated against hepatitis B. Hepatitis B vaccination usually means that the body has been vaccinated against hepatitis B virus. Hepatitis B vaccination usually refers to injecting attenuated or inactivated pathogens directly into the body, thus stimulating the immune cells to produce corresponding immune responses and generate hepatitis B antibodies. Positive surface antibodies to the hepatitis B virus indicate that the body has a certain degree of resistance and is therefore less likely to become infected, but self-protection and regular check-ups are still recommended.