Objective: To investigate antioxidant activity of water extract and alcohol extract of Eriocauli Flos. Method: Scavenging effect of water extract and alcohol extract of Eriocauli Flos on superoxide anion free radical

DPPH radical and hydroxyl radical were determined by UV method

reduction ability of extract for Fe3+ was determined by Prussian law

and with butylated hydroxyanisole (BHA) as reference

chelating ability of extract on metal ferrous ion (Fe2+) was determined. Result: Water extract and alcohol extract of Eriocauli Flos had strong scavenging effects on three kinds of free radicals

half inhibitory concentrations (IC50) of water extract were 1.389

3.507

0.341 g ·L-1

while IC50 of alcohol extract were 0.792

5.525

0.192 g ·L-1.Extract had reduction ability on Fe3+

and had a strong chelating ability to Fe2+

effects increased with increasing of extract concentration

which showed corresponding dose-response relationship. Conclusion: Water extract and alcohol extract of Eriocauli Flos have strong antioxidant activity

and at a relatively low concentration

alcohol extract is stronger than water extract about antioxidant effect.