Hepatitis B antigen and antibody are of various types, and being positive at the same time may indicate the existence of hepatitis B virus infection, replication or different subtypes of hepatitis B virus infection. 1. Existence of viral infection: Hepatitis B antigens commonly detected in clinic include hepatitis B virus surface antigen, e antigen and core antigen; antibodies correspond to antigens, and there are hepatitis B surface antibodies, e antibodies and core antibodies; when antigens and antibodies are positive at the same time, it suggests the existence of hepatitis B virus infection. 2. Viral replication: when hepatitis B virus surface antigen is positive with positive core antibody, it suggests that it is in the viral replication period of acute and chronic infection of hepatitis B virus; when hepatitis B virus surface antigen is positive with positive anti-e antibody, it suggests that the viral replication is weakened or stopped. 3. Different subtypes of hepatitis B virus infection: when hepatitis B virus surface antigen is positive with anti-surface antibody, it suggests the existence of different subtypes of hepatitis B virus infection. Therefore, when the antigen and antibody are positive at the same time, timely diagnosis and treatment should be made to avoid delaying the condition.