Collagen peptide was prepared from Navodon septentionalis bone by applying bromelin as a catalyst. Navodon septentionalis bone was mixed with 1%bromelin (w:w)and water at a ratio of 1:4 (w/w).The mixture was incubated at 60°Cfor 4 hours. The dehydration degree was up to 26.20% on optimum condition and the concentration of polypeptide was almost 50mg/ml. The antioxidant activity was investigated and compared with vitamin C, TBHQ, BHA and BHT. Collagen polypeptide at 50mg/ml and 10mg/ml exhibited 80% and 92.5% of scavenging activities on hydroxy radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, respectively.