 Influence of antiviral treatment to the long term prognosis of patients with chronic HBV infection. The aim of antiviral treatment for HBV is to reduce the long term severe complications. In this study, the investigators divided patients with chronic HBV infection into two groups, which start early antiviral treatment and conventional antiviral treatment respectively. All the patients will be followed for ten years. From this study, the investigators want to find out the optimal time for patients with chronic HBV infection to start antiviral treatment. 