 Chronic hepatitis B CHB is a serious liver disease worldwide, and the leading cause of cirrhosis and hepatocellular carcinoma HCC.HBsAg lossseroconversion is considered to be the ideal endpoint of antiviral therapy in both HBeAg-positive and HBeAg-negative patients, as well as the ultimate treatment goal in CHB. However, some patients who have achieved HBsAg loss would reverse back to HBsAg positive, or even become HBV reactive with recurrence of viremia. In current study, the viral and HBsAg response in patients who have achieved HBsAg loss by interferon IFN treatment will be observed for 96 weeks after the completion of IFN treatment. The primary analysis will be performed at the end of 96 weeks. Following the completion of the study period of 96 weeks, patients will be offered to participate in a long term study for further observation of additional 144 weeks total of 240 weeks from the enrollment. 