The antioxidant activities of alpha-hederin and hederasaponin-C from Hedera helix, and hederacolchisides-E and -F from Hedera colchica were investigated, in this study. The antioxidant properties of the saponins were evaluated using different antioxidant tests: 1,1-diphenyl-2-picryl-hydrazyl (DPPH.) free radical scavenging, total antioxidant activity, reducing power, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. alpha-Hederin, hederasaponin-C, as well as hederacolchisides-E and -F exhibited a strong total antioxidant activity. At the concentration of 75 mug/mL, these saponins showed 94, 86, 88 and 75% inhibition on lipid peroxidation of linoleic acid emulsion, respectively. These various antioxidant activities were compared with model antioxidants such as alpha-tocopherol, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).