Abstract: The antioxidant peptides from enzymolysis of deer blood are isolated and purified, and the size exclusion method (SEC) of high performance liquid chromatography (HPLC) is used to determine molecular weight and to analyze amino acid composition of the peptides.By the isolation and purification of SephadexG-25 and DEAE-52 column, the antioxidant peptides with weak negative charge are obtained. The HPLC results indicate that the antioxidant peptides are small peptide mixture with low molecular weight, mainly includin gpeptides with relative molecular weights of 876 Da, 463 Da and 146 Da. The amino acid composition analysis indicates that the antioxidant peptides contain 17 kinds of amino acids in which Leu, Lys and Ala contents are higher, i.e., 17.2%, 12.3% and 12.1% respectively, and the content of amino acids (Val, Ile, Leu, Phe, Met, Thr and Lys) essential to human body is up to 52.7%.