Abstract: Preliminary identification of polyphenols from old leaves of Chinese mahogany (Toona sinensis (A. Juss) Roem (TP)) had been made and four antioxidant testing methods, namely: reductive power measurement, ferric reducing ability of plasma (FRAP) method, DPPH radical scavenging activity measurement and β-carotene bleaching method, were tested respectively to study antioxidant ability of TP. Results of reductive power measurement and FRAP method showed that absorbances under wave length λ 700 and 593 nm respectively of TP were higher than that of butylated hydroxy toluene(BHT) which proved that TP owned a stronger antioxidant ability. Results of DPPH radical scavenging ability measurement were all above 90%, as high as those of Vc. Result of β-carotene bleaching method indicated that TP showed an apparently dosage-dependent relationship and strong antioxidant ability.

Key words: Toona sinensis(A. Juss) Roem, polyphenols, antioxidant