Objective: To clarify the antioxidative effects in vitro of Ginseng Radix et Rhizoma

Ophiopogonis Radix and Schisandrae Chinensis Fructus from Shengmai San. Method: With the use of superoxide anion (O2-·) H2O2 and ONOO- generation system

reactive oxygen species (ROS) scavenging effect of Ginseng Radix et Rhizoma

Ophiopogonis Radix and Schisandrae Chinensis Fructus was analyzed in offline mode; furthermore

three online ROS systems including HPLC-luminol-H2O2-CL

HPLC-luminol-pyrogallol-CL

HPLC-ONOO--luminol-CL were used to analyze the direct scavenging effect of Ginseng Radix et Rhizoma

Ophiopogonis Radix and Schisandrae Chinensis Fructus on O2-·

H2O2 and ONOO-

and clarify its effective components and antioxidative characteristics. Result: Water-soluble components could be the main constituents in scavenging three ROS

and lipophilic component exerted little effect on scavenging ROS. Conclusion: Three constituents with direct ROS scavenging effect were clarified with use of 3 ROS online scavenging systems

and the effect of directly scavenging ROS could be not the main effect of Shengmai San

providing basis and new thoughts for further study on mechanism of Shengmai San in preventing and treating myocardial ischemia injury.