The hepatitis B two-to-one test, also known as the five hepatitis B tests, is a laboratory test used to determine the presence and extent of hepatitis B virus infection, and consists of five parts: hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen, hepatitis B e antibody, and hepatitis B core antibody. The presence of hepatitis B surface antigen is a kind of hepatitis B virus shell material which is not infectious, and when the test is positive, it indicates the presence of intact virus particles, and patients with chronic hepatitis B often have persistent positivity. When positive, it indicates that the virus is active and is also an indicator of infectiousness; hepatitis B e antibody is a protein produced in response to the e antigen, and when positive, it often indicates that the person is recovering from infection; hepatitis B core antibody usually appears 3-5 weeks after the appearance of surface antigen, and is a laboratory test that appears earlier than the appearance of hepatitis B symptoms. The five parts of hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B e antigen, hepatitis B e antibody, and hepatitis B core antibody are the contents of the hepatitis B half test, which can be used not only to determine the presence or absence of hepatitis B infection, but also to assess the efficacy of hepatitis B antiviral therapy.