Chitosan is widely distributed in nature and is a β-1,4-linked D-glucosamine (GlcN) derived from either partial or complete deacetylation of chitin (β-1,4-linked N-acetyl D-glucosamine,GlcNAc).Utilizing chitosan is advantageous because of its high solubility in acidic solution,and chitooligosaccharides as hydrolysis products of chitosan have received interests because they provide functional properties such as antimicrobial activity,antitumor activity,immunoenhancing effects,and potential additives for manufacturing functional foods.