Abstract:Under the optimum conditions using glutathione and ascorbic acid as the controls， DPPH· and phenanthroline-Fe2+ oxidation assays were applied to evaluate the capacities for scavenging free radicals of fish skin oligopeptides. Determination of amino acid composition of fish skin oligopeptides put to use the GB/T 5009.124-2003 （Determination of amino acids in foods） method. The relationship between antioxidative activity and amino acid composition of fish skin oligopeptides was analyzed， and the nutritional values of those were evaluated. The results showed that the values of half-inhibitory concentration （IC50） of fish skin oligopeptides， glutathione and ascorbic acid for·OH were 2.482， 0.357， 0.100 mg/mL， respectively， and those for DPPH· were 0.635， 0.030 and 0.003 mg/mL， respectively. Essential amino acids contents of fish skin oligopeptides were 24.43 %， EAA/TAA was 24.19 %， EAA/NEAA was 32 %， CS was greater than 100， and EAAI was 352. Sulphur amino acids contents were 3.8 %， hydrophobic amino acids except methionine accounted for 26.7 % of total amino acids， so the total antioxidative activity amino acids were 30.5 % which was consistent with the antioxidative activity of fish skin oligopetides.