Hepatitis B 125 positivity refers to the positivity of hepatitis B surface antigen, hepatitis B surface antibody, and hepatitis B core antibody, and is often indicative of an early stage of subclinical hepatitis B virus (HBV) infection, or a different subtype of HBV infection. Positive hepatitis B surface antigen indicates infection with the hepatitis B virus, but does not indicate whether the lesion belongs to a patient with hepatitis B or a carrier of the hepatitis B virus, only that there is hepatitis B virus infection. Surface antibodies (anti-HBs) are protective antibodies against the hepatitis B virus, indicating that immunity to the hepatitis B virus has been developed, and some people also produce anti-HBs automatically after infection with the hepatitis B virus. Rarely, both surface antigen and antibodies are positive, as seen in different subtypes of hepatitis B virus infection. Core antibody (anti-HBc) positivity indicates a previous or current infection with the hepatitis B virus. As long as one has been infected with the hepatitis B virus, the core antibody (anti-HBc) is positive, and there are two subtypes: anti-HBcIgM and anti-HBcIgG. Hepatitis B 125-positive patients are advised to take further tests for liver function and hepatitis B DNA to clarify their condition and take treatment measures if necessary.