The antioxidative activities of hydrolysates isolated from the freshwater rotifer using enzymes Alcalase, $alpha$-chymotrypsin, Neutrase, papain, pepsin, and trypsin were identified and evaluated using direct free radical scavenging activity. Among the six hydrolysates, Neutrase hydrolysate had the highest antioxidative activity compared to the other hydrolysates. The free radical scavenging activity of Neutrase hydrolsysate was 45.26% at 1.0mg/mL. The peptide demonstrating the strongest antioxidative activity was isolated from the hydrolysate using consecutive chromatographic methods including Sephadex G-25 Gel chromatography and high performance liquid chromatography on an ODS column. The $IC_{50}$ value of purified antioxidant peptide was 100.8 ${mu}M$. The antioxidant peptide was identified as a sequence of 10 amino acids, Gly-His-Asp-Gly-Tyr-Glu-Pro-Leu-Ser-Ser (1091 Da) by N-terminal amino acid sequence analysis. The purified peptide exhibited an inhibitory effect against induced DNA oxidation. Our results suggested that antioxidative hydrolysates freshwater rotifer may be useful ingredients in food and nutraceutical applications.