Hepatitis B two pairs of half refers to hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen, hepatitis B e antibody and hepatitis B core antibody. The hepatitis B two-to-one test can indicate the following points: first, the status of hepatitis B virus infection can be seen; second, whether the patient is infected after contact with hepatitis B patient or hepatitis B virus; third, whether protective antibodies are produced after performing hepatitis B vaccination. If hepatitis B surface antigen, hepatitis B e antigen and core antibody are present at the same time, it is the so-called major triple yang; if hepatitis B surface antigen, hepatitis B e antibody and hepatitis B core antibody are positive at the same time, it is the so-called minor triple yang. If the hepatitis B surface antibody alone is positive, it indicates that the vaccination was successful; if the hepatitis B core antibody alone is positive, it indicates that the person has a previous hepatitis B infection.