Abstract: Effecs of inositol triphosphate （IP3）on scavenging free radicals were identified by electron paramagnetic resonance （EPR）spectroscopy.In Fenton reaction system.the scavenging rate of （OH）by IP:（produced by baker’s yeast ）In 6mg/ml was 75.34%. the scavenging rate of （OH）by IP3（produced by phytase） in 9mg/ml was 73.29%.In HX-OX reaction system .the scavenging rate of（O）by IP3（produced by baker’s yeast ）in 18mg/ml was 72.76%.the scavenging rate of （O.2） by IP3（produced by phytase ）in 9mg/ml was 53.84％. It was deduced that.thc reason why IP3 could be used as a curative for preventing alleviating or combating several diseases was that IP3 could scavenge free radicals efficiently.

Key words: Inositol, Triphosphate, Free radical, Scavenging