Long-acting interferon has both antiviral and immunomodulatory effects and is currently the first-line clinical antiviral drug for hepatitis B. Its efficacy features include a limited course of therapy, the opportunity to obtain better efficacy results, and stable efficacy that is less likely to recur. Patients with chronic hepatitis B have a higher serological conversion rate of e antigen and a higher clearance rate of surface antigen after a limited course of long-acting interferon therapy, and a lower incidence of cirrhosis and hepatocellular carcinoma. Compared to nucleoside (acid) drug therapy, interferon not only has a direct antiviral effect, but more importantly, it achieves antiviral efficacy by stimulating the patient’s immune response, so the efficacy is stable and less likely to relapse after discontinuation of the drug. The interferon is a limited course of treatment, compared to the nucleoside (acid) class of long-term dosing, there is no risk of drug resistance also avoids the increasing burden of treatment. However, the efficacy of interferon may vary from patient to patient because of individual differences. Therefore, before, during and even after treatment with interferon, the doctor will recommend that the patient undergo a test to find out whether the patient is suitable for interferon treatment on the one hand, and to see how effective the patient will be after treatment and what the chances of success are on the other. What are the tests? Patients with high ALT levels and low viral quantification have a higher chance of serological conversion to e antigen with interferon therapy. The results of the study suggest that those with a significant decrease in surface antigen quantification at 24 weeks of treatment have a higher rate of e antigen serological conversion at 24 weeks after discontinuation of the drug. Of course, it is not necessary to be discouraged if the review reveals that the treatment is not effective at 24 weeks, and the treatment plan should be adjusted according to the response, for example, the combination of nucleoside (acid) drugs can improve the efficacy. A more specific approach to review can be found in the following time points: Liver function, including glutamate aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, etc. Once a month for the first 3 months of treatment, and may be done every 3 months thereafter. Viral quantification and hepatitis B markers. Viral quantification will be done once a month for the first 3 months and may be done every 3 to 6 months thereafter. Hepatitis B quantification, especially surface antigen quantification, will be done every 3-6 months. In addition, some adverse effects may occur after interferon therapy, such as neutropenia and thrombocytopenia, autoimmune disease, fever, and malaise. Targeted examination at the time of review can detect these adverse reactions as early as possible and give timely treatment to ensure smooth treatment. Review of interferon-related adverse reactions: Blood tests: 1 test every 1~2 weeks in the first month, then 1 test every month until the end. Thyroid function, blood glucose, urine routine, anti-nuclear antibody: tested once every 3 months (if thyroid abnormality or diabetes is present before treatment, it should be tested once a month). Mental status: should be closely observed at each follow-up visit. Interferon treatment for slow hepatitis B is unanimously recommended by domestic and international guidelines and can help patients achieve good results of durable response after drug discontinuation. Regular review during treatment to keep track of treatment response and give accurate guidance on treatment plan; early detection and management of adverse reactions to ensure smooth treatment will help us to improve the success rate of interferon treatment.