Chitosan oligosaccharide has accelerated epidermal cell metabolism and regeneration, and excellent heat preservation and moisture absorption function, can effectively stop the skin rough and ageing. The chitosan oligosaccharides also has antibacterial anti ultraviolet absorption function and skin disease. Especially for acne have a good effect. In hair care products in addition of chitosan oligosaccharide can keep hair membrane permeability, moist, easy to comb and antistatic, anti dust, anti itching to dandruff. Chitosan oligosaccharide good chemical stability, and emulsifier, surface activity of compound has good performance, and can increase the absorption of the scalp, so chitosan oligosaccharide is widely used in cosmetics.