Chitosan oligosaccharide is a kind of oligosaccharide product with polymerization degree between 2 and 20, which is degraded by special biological enzyme technology (also reported by chemical degradation and microwave degradation technology). Chitosan oligosaccharide is the only cationic basic amino oligosaccharide with positive charge in nature, which is animal cellulose. Character Chitosan oligosaccharide is made from chitosan depolymerization, which is an upgraded product of chitin and chitosan, and has incomparable advantages over chitosan. It has the advantages of low molecular weight, good water solubility, great function, easy to be absorbed by the human body and high biological activity. At the same time, it has the characteristics of pure natural, no radiation, no pollution and no addition. The molecular weight is ≤ 3200Da. It is a low molecular weight product with good water solubility, great function and high biological activity. It has many unique functions, such…