At present, the vast majority of medical institutions use the more sensitive chemiluminescent method for quantitative testing of the five hepatitis B items. When the hepatitis B surface antigen result is greater than 250ng/mL, it indicates that the tested serum has hepatitis B surface antigen, which means that the hepatitis B surface antigen is positive. Hepatitis B surface antigen quantification >250 indicates that the person tested is infected with the hepatitis B virus, and further testing of hepatitis B virus DNA, liver function and liver ultrasound is still needed to determine whether anti-hepatitis B virus treatment is required. The highest detection limit of the chemiluminescence test for hepatitis B is 250 ng/mL. If the concentration of surface antigen in the tested serum is higher than 250 ng/mL, the result will be >250 ng/mL, and further quantitative dilution of hepatitis B surface antigen will be done to detect its specific concentration value.