Objective: To evaluate the oxidative stress status and its clinical significance in patients with chronic hepatitis B.Methods: Total antioxidant response and malondialdehyde level were measured and oxidative stress index was calculated in 42 patients with chronic hepatitis B,30 inactive carriers and 22 healthy controls.Results: Malondialdehyde(MDA) and oxidative stress index(OSI) were significantly higher in chronic hepatitis B patients than in inactive HbsAg carriers and controls(P0.05,P0.05,P0.01,P0.01).Total antioxidant response was comparable in chronic hepatitis B subjects,inactive HbsAg carriers and controls(both P0.05).MDA and oxidative stress index were also comparable in inactive HBsAg carriers and controls(both P0.05).Serum alanine aminotransferase level was positively correlated with malondialdehyde concentration and oxidative stress index only in chronic hepatitis B subjects(r=0.61 and r=0.45,respectively),and there was no significant relationship between HBV-DNA and oxidative stress.Conclusion: There are disturbances of oxidative stress and antioxidativestress in the chronic hepatitis B.The detection of oxidative stress is essential to clinic.