What is meant by “Australian antigen positive”? The Australian antigen is an antigenic substance originally found in the sera of native Australians and is referred to as “Australian antigen”. Later, it was observed that this antigen was often found in the sera of patients with viral hepatitis, so it was also called hepatitis-associated antigen (HAA). Later, after repeated studies by experts from various countries, it was found that HAA only appeared in hepatitis B and was not related to hepatitis A. In order to avoid confusion, the HAA was identified by the World Health Organization Hepatitis Specialists. To avoid confusion, it was officially named “hepatitis B surface antigen” by the World Health Organization Hepatitis Specialized Conference. The hepatitis B virus shell part contains surface antigen, that is, hepatitis B surface antigen, after a person is infected with the hepatitis B virus, there is often a large amount of surface antigen remaining in the blood, forming surface antigenemia. The surface antigen itself is not the complete hepatitis B virus, but the shell of the hepatitis B virus, which is not infectious in itself but has antigenicity, it is only one of the signs of hepatitis B virus infection. In 1965, Professor Bumberg found a special antibody in the serum of a patient with hemophilia who had received several blood transfusions. The antibody could only react with the serum of local Australian residents, so it was thought that these Australians had a special antigen in their bodies, which was then named Australian antigen, or HBsAg for short. In 1970, Dane et al. The Dane particles were identified as hepatitis B virus particles under electron microscopy, and further elucidated that they were spherical particles with a diameter of 42 nm, a 7 nm thick shell composed of protein and membrane fingerprint, which is the envelope of the virus, and a 28 nm diameter core containing DNA polymerase in addition to deoxyribonucleic acid. The HbsAg, which was discovered in 1965, has been replaced by HbsAg, and the name “Australian Antibody” or HAA is now history. At present, the markers associated with the virus in the serum of hepatitis B patients can be detected clinically, including hepatitis B virus surface antigen (HbsAg), hepatitis B virus surface antibody (anti-HBs), hepatitis B virus core antibody (anti-HBc), hepatitis B virus E antigen (HbeAg), hepatitis B virus e antibody (anti-Hbe), (the above five combined tests are commonly known as the “hepatitis B five”) hepatitis B virus DNA (HBV-DNA), etc. Although the term “Ao antibodies” has become obsolete, and even many young doctors do not understand what “Ao antibodies positive” is all about, it is still customary to say “Ao antibodies positive” among people who are a little older. The so-called “AoA positive” is a positive test for hepatitis B virus surface antigen (HbsAg), which means a person with chronic hepatitis B virus infection. In the past, many primary care hospitals only tested for hepatitis B virus surface antigen (HbsAg) during physical examinations, and only those who were positive for hepatitis B virus surface antigen (HbsAg) were further examined, often lay doctors did not pay enough attention to hepatitis B virus surface antigen (HbsAg) positivity, leading to many misconceptions among the public. The simple HbsAg positivity is not a big problem and should be ignored, right? The so-called simple HbsAg positive refers to hepatitis B carriers with normal liver function (please refer to my article “What is the concept of “hepatitis B carriers”). When symptoms are detected, they are already at an advanced stage of liver disease. I’m not infectious, right? In the past, many patients were afraid of being discriminated against, so they always avoided treatment and claimed that “I am only Ao-positive, I don’t need treatment and I am not contagious”, which led to untimely treatment and delayed illness. The purpose of this article is to popularize the concept of “AoA-positive” for older patients with chronic hepatitis B infection and younger doctors.