In a previous study, we found that Inchenhau-Tang (ICHT) is the most strong anti-oxidant among twelve herb drug prescriptions that are commonly used in treatment of liver disease. ICHT is mostly used in treatment of acute hepatitis with jaundice. Therefore, in this study we further investigated the scavenging effect of ICHT on the oxygen radicals, including superoxide anion (O2 (superscript -)) and hydrogen peroxide (H2O2) in the whole blood of patients with acute hepatitis. We also investigated the anti-oxidative effect of Artemisiae Capillaris Herba (ACH), Gardeniae Fructus (GF), and Rhei Rhizoma (RR) which are composed of ICHT. The results show that the water extract of ICHT significantly scavenged both superoxide anion and hydrogen peroxide in the whole blood of patients with acute hepatitis. The scavenging effect of ICHT on superoxide anion was greater than that on hydrogen peroxide. Furthermore, all of water extracts of three composed herb drugs significantly scavenged superoxide anion produced by xanthine/xanthine oxidase, and markedly inhibited the production of lipid peroxide from rat liver cells induced by FeCl2. Among them, RR had the most strong anti-oxidative effect. The above results revealed that water extract of ICHT can scavenge oxygen radicals in the whole blood of patients with acute hepatitis. Among three composed herb drugs of ICHT, RR is a most important antioxidant.