(A) Liver failure due to hepatitis B Since most acute hepatitis B has a self-limiting course, routine antiviral therapy is not required. However, antiviral therapy should be given to some severe or prolonged cases with a tendency to severe disease. Liver failure due to HBV infection, whether acute, subacute or slow-plus-acute liver failure, etc., should be treated with antiviral therapy with nucleoside (acid) analogues as long as HBV DNA is detectable. (ii) Primary hepatocellular carcinoma (HCC) caused by hepatitis B. Preliminary studies have shown that HBV DNA level at the time of hepatectomy for HCC is one of the independent risk factors for predicting postoperative recurrence, and antiviral therapy can significantly prolong the survival of hepatocellular carcinoma; therefore, antiviral therapy with nucleoside (acid) analogues is recommended for patients with HBV DNA-positive non-end-stage HCC. (iii) Patients with decompensated hepatitis B cirrhosis The indications for treatment are positive HBV DNA and normal or elevated ALT. The goal of treatment is to improve liver function by inhibiting viral replication in order to delay or reduce the need for liver transplantation. Antiviral therapy can only delay disease progression, but cannot by itself change the final outcome of end-stage cirrhosis. Interferon therapy can lead to liver failure and is a contraindication. In patients with decompensated cirrhosis with active viral replication and inflammatory activity, lamivudine therapy may be given to improve liver function based on their informed consent, but it should not be discontinued at will. In case of resistance mutation, other approved nucleoside (acid) analogues that can treat the resistance mutation should be added promptly. (d) Patients with compensated hepatitis B cirrhosis The indications for treatment are HBV DNA ≥104 copies/ml for HBeAg-positive patients and HBV DNA ≥103 copies/ml for HBeAg-negative patients, with normal or elevated ALT. The goal of treatment is to delay and reduce the occurrence of liver failure and HCC. Because of the need for longer-term treatment, nucleoside (acid) analogs with a low incidence of drug resistance are preferable, and their discontinuation criteria are not known. Interferon should be used with great caution because of its potential to cause complications such as hepatic failure. If deemed necessary, it is advisable to start with a small dose and gradually increase it to the intended therapeutic dose according to the patient’s tolerance.