In the clinical treatment of chronic hepatitis B, antiviral therapy is the key to treatment. Many patients have many questions about the treatment course of nucleoside antivirals (such as lamivudine, adefovir, telbivudine, entecavir, etc.), which are explained below according to the current new treatment guidelines around the world in the hope that they will be helpful to the majority of patients. The new Clinical Practice Guidelines for Chronic Hepatitis B published by the European Association for the Study of the Liver (EASL) in 2009 set the goals of treatment as: to improve quality of life, prolong survival, and stop and delay the onset of cirrhosis, decompensated liver disease, end-stage liver disease, liver cancer, and death. Antiviral therapy is the primary means of achieving this goal. Antiviral therapy requires long-term treatment, but long-term treatment is not the same as lifelong treatment, and many patients wish to receive short-term treatment, which requires clear treatment endpoints and regimens. Endpoints and regimen of antiviral therapy The ideal treatment endpoints are clearly defined in the new guidelines as the persistent disappearance of hepatitis B virus surface antigen (HBsAg) with or without serologic conversion to HBs (appearance of HBsAb) in HBeAg-negative patients. For HBeAg-positive patients, durable HBeAg serologic conversion (conversion of HBeAg to HBeAb) is a satisfactory treatment endpoint; for patients who do not achieve HBeAg serologic conversion, maintenance of HBVDNA at undetectable levels is a secondary treatment endpoint. The ’07 American Association for the Study of the Liver (AASLD) treatment guidelines state that the treatment endpoint for HBeAg(-) patients is also the disappearance of HBsAg; the treatment endpoint for HBeAg(+) patients is at least 6 months after HBeAg serologic conversion (conversion of HBeAg to HBeAb). The ’08 Asia-Pacific Society for the Study of the Liver (APASL) guidelines state that the treatment endpoint for HBeAg(-) patients is testing every 6 months and 3 consecutive HBVDNAs at undetectable levels; the treatment endpoint for HBeAg(+) patients is HBeAg serologic conversion (conversion of HBeAg to HBeAb) and testing every 6 months 1 time every 6 months, with 2 consecutive HBVDNAs reaching undetectable levels. The question of which patients are suitable for antiviral therapy and which patients can withhold antiviral therapy (indications for antiviral therapy) will be covered in a future article.