Abstract: Objective:To observe the clinical efficacy and safety of peginterferon α-2a in treatment of chronic hepatitis B.Methods:Two patients with chronic hepatitis B were treated with peginterferon α-2a;and the blood,HBV viral markers,HBV-DNA and liver function were tested regularly during the therapy.Results:One patient demonstrated negative HBeAg at 12 weeks,HBeAg seroconversion at 48 weeks,and HBV-DNA was undetectable at the same time.The other patient had undetectable HBV-DNA at 6 weeks,negative HBsAg at 12 weeks,and HBeAg seroconversion at 24 weeks.Conclusions:Peginterferon α-2a can regulate the immune response and obtain serum e/s antigens clearance or conversion in a limited treatment course.Peginterferon α-2a is effective on patient with chronic hepatitis B.