HBV-DNA is a more important test to determine whether the hepatitis B virus is replicating and the level of replication, and is an important basis for deciding whether to administer antiviral treatment and judging the efficacy of treatment in patients with chronic hepatitis B virus infection, as well as an important indicator to determine the infectiousness of chronic hepatitis B virus infection. Currently, for HBV-DNA testing, most hospitals use a quantitative method, and the report form consists of the test result, units, and reference range. In the case of qualitative tests, the result is usually negative and positive. The report card is viewed differently depending on the test method.1. Qualitative test: If the report card is negative, it indicates normal. If the report card is positive, it indicates the presence of hepatitis B virus in the patient’s body and the possibility of transmission. But qualitative examination is not detailed and precise enough, it is recommended to do quantitative examination of hepatitis B virus; 2. Quantitative examination: due to the inconsistency of testing methods used by different medical institutions, there are certain differences in HBV-DNA testing units and normal value ranges. Some hospitals use the unit of copies/ml, while others use IU/ml, with the latter being used more often at present. The former corresponds to a normal reference value of less than 5.00E+02 or 1.00E+03, while the latter is less than 1.00E+02 or less than 20 IU/ml. less than 1.00E+02 IU/ml is usually for domestic kits, and less than 20 IU/ml is for imported kits. The value of E+02 in the reference value refers to the 2nd power of 10. The value in the HBV-DNA report sheet, if it is less than the normal reference value, it means that the replication level of hepatitis B virus DNA is very low, basically no replication. If the test result is higher than the reference value, it means that there is replication of hepatitis B virus in the body. The higher the level of HBV-DNA, the stronger the replication ability and the more infectious it is. The need for antiviral treatment also needs to be combined with the results of liver biochemistry, ultrasound, liver elastography and, if necessary, pathology results from liver puncture. Patients who have hepatitis B virus infection need to visit the hospital regularly and follow medical advice for conservative observation or treatment.