The abilities of scavenging active oxygen species,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650436&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650438&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42650437&type=, and OH,·, by tea polyphenols and quercetin have been studied by chemiluminescene, ESR and pulse radiolysis. Tea polyphenols and quercetin are all phenolic antioxidants. The synergetic studies show that both tea polyphenols and quercetin are strong free radical scavengers. Tea polyphenols are better than quercetin. The results from CL studies are in good accord with those from ESR and PR studies.