Abstract: Citrus Bergamots fruit and leaf were used as materials for determination of flavonoids clearance of superoxide anion free radical, hydroxyl radical and DPPH radical in order to investigate the antioxidant capacity in vitro. The results showed that the scavenging capacity of DPPH radical of fruit and leaf flavonoids IC50 were 8.25 and 9.03 mg·L-1 respectively, which were lower than Vc and rutin. Their superoxide anion free radical scavenge capacity IC50 were 17.74 and 20.77 mg·L-1 respectively, which were higher than rutin, but lower than Vc. Their hydroxyl radical scavenge capacity IC50 were 17.06 and 15.86 mg·L-1 respectively, which were higher than Vc, and as much as rutin. The results of variance analysis showed that there is a significant difference in scavenging rate of superoxide anion free radical and hydroxyl radical among different concentrations of fruit and leaf flavonoids. With the increasing concentration of fruit and leaf flavonoids in the reaction solution, the scavenging rate of superoxide anion free radical showed an increasing trend. But when the concentration reached a certain one, the increasing trend of scavenging rate became slower. The best dose for scavenging hydroxyl radical of fruit and leaf flavonoids was 18 mg·L-1．

Key words: Citrus Bergamot, flavonoids, antioxidative, scavenging