Collagen, which is widely distributed in pluricellular animals, is one of the most fundamental constituents of the extracellular matrix, and plays mechanically or physiologically important roles in their bodies. In this study, the biochemical and physical characteristics of pepsin-solubilized collagen from the mantle of Yesso scallop (YMPC), a by-product of processing, was determined. Electrophoretic patterns showed that scallop mantle collagen contained a1 and a2 chains, which was similar to the patterns of bovine tendon type V collagen. The YMPC showed different profiles in molecular, amino acids, peptide maps from those of bovine tendon collagen and lower denaturation temperature. Electron microscopic view of YMPC showed a sponge-like structure in part. These results indicated that YMPC may become a sustainable source of useful collagens for various purposes including value-added biomaterials. It may also be useful in a variety of applications as an alternative of vertebrate collagen, which has been widely used.