The scavenging effects of Total Flavonoids of Hippophae ( TFH ) were studied by using ESR-spin trapping technique in different systems, and the inhibitery effects on chemiluminescence ( CL ) of poly-morphonuclear leukocytes ( PMN) were measured by using luminol-de-pendent CL. TFH ( 1.7mg/L ) significantly reduced the active oxygen radicals level of PMA-stimulated PMN; TFH ( 0.03-3mg/L ) could remarkably scavenged O2 in xanthine/xanthine oxidase (Xan/XO)system and the effect was concentration-dependent. The scavenging effect of TFH on O2 in irradiation riboflavin system was not so strong as in Xan/XO system. TFH ( 3 mg/L ) could scavenged OH produced in Fenton's reaction; TFH ( 1 mg/L ) effectively inhibited PMN CL stimulated by PMA.The effects of TFH on active oxygen radicals produced by PMN and O2 in Xan/XO system were stronger than Vit E.