1.Lamivudine (Herceptin) The earliest nucleoside (acid) class drug used against hepatitis B virus, marketed in China in 1999, is by far the most cumulative cases of oral anti-hepatitis B virus drugs. Lamivudine has a rapid onset of action, strong viral suppression, and is relatively inexpensive, but is not recommended for first-line use due to the high incidence of drug resistance. Caution: Since long-term use is prone to mutation and leads to drug resistance, it should be reviewed regularly (recommended every 3 months) during treatment. Clinical data for 1 year of drug use: serum HBV-DNA conversion rate is 46%-70%, ALT normalization rate in liver function is 41%-75%, and e antigen seroconversion rate is 16%-21%. Drug resistance status: 20% at 1 year, 80% at 5 years. 2.Adefovir (Haverix, Daidin, Meizheng, Agmatine, Ugandine, Adesian) was launched in China in 2005. The main feature of Haverix is that its resistance sites do not cross with other nucleoside analogues, and it is more suitable for patients with YMDD (site 204) variation. However, adefovir has weak antiviral ability, slow onset of action, and potential nephrotoxicity with long-term use, and is mainly used as a salvage drug. Caution: Long-term use may harm the kidney; not recommended for patients under 18 years of age. Clinical data for 1 year of drug use: serum HBV-DNA conversion rate of 21%-51%, ALT normalization rate of 48%-72% in liver function, e antigen seroconversion rate of about 12%. Drug resistance: 0% at 1 year, 11% at 3 years, 29% at 5 years. 3, Entecavir (Boludin) Boludin was launched in China in 2005, with rapid onset of action, strong viral suppression, and very low viral mutation rate, and is recommended as the first-line drug of choice by the latest major domestic and international guidelines (2012 European Liver Institute, 2012 American College of Hepatology, 2012 Asia Pacific Liver Institute and China 2010 guidelines). The efficacy of this drug has been recognized by many physicians. Caution: Use with caution under 16 years of age and fasting 2 hours before and after dosing. Clinical data of 1 year of drug use: the rate of serum HBV-DNA disappearing and turning negative is 70-87%, the rate of ALT normalization in liver function is 67-78%, the rate of e antigen seroconversion is about 21%; drug resistance: 0.4% at 2 years, 1.1% at 3 years, 1.2% at 6 years for patients with initial nucleoside (acid) analogues. 4.Tibivudine (Sulbivir) has a strong viral inhibitory effect. The disadvantage is that the incidence of drug resistance is high. In addition, the safety performance of telbivudine is not satisfactory. It is the only FDA-approved drug in China for pregnancy class B. Other nucleoside (acid) drugs are class C. It is better than lamivudine for maternal and infant blockade. May have a protective effect on renal function. Caution: Myotoxicity (elevated CK). Increased peripheral neuropathy in combination with interferon. Lack of data from long-term clinical studies. Clinical data at 1 year of dosing: serum HBV-DNA disappearance conversion rate of 60-88%, ALT normalization rate of 72-74% in liver function, e antigen seroconversion rate of about 22%. Drug resistance: 5% in HBeAg-positive patients at 1 year, 22% at 2 years, and 8.6% in HBeAg-negative patients at 2 years.