Abstract: Collagen peptide is a type of peptides complex with rich nutritive value and biological functions derived from hydrolysis of collagen. Based on the debate in recent years that whether it is useful to supply collagen, this article provides comprehensive description of collagen peptide and collagen from the aspects of structure composition and functional properties and applications. Collagen peptide products that have been applied in food industry and health care field in recent years were reviewed. A significant body of this work had been devoted to the statements about digestion absorption properties, nutritive value and biological function of collagen hydrolysates. The outlook for prospect and developing priority of collagen peptide were described. Ultimately, this review can serve as a reference for the exploration and utilizing of collagen peptide.