Hyaluronic acid is a kind of hyaluronic acid (HA), also known as uronic acid. Natural hyaluronic acid is a kind of macromolecular polysaccharide, which is a linear macromolecular polysaccharide with glucuronic acid -N- glucosamine acetate as disaccharide molecular unit. Its average molecular weight is between 6,543.8+10,000 and 6,543.8+10,000 daltons, and it exists in intercellular spaces. Originally used only for moisturizing, it has now been included in the ranks of wrinkle removal and plastic surgery. This plastic surgery technique is to inject hyaluronic acid, which is non-animal stable and cultured by bacterial fermentation, into wrinkles and depressions of dermis or parts that want to be full, to remove wrinkles and modify the face, which can immediately remove wrinkles and change appearance. Hyaluronic acid, which originally exists in the dermal tissue of human skin in the form of colloid, is responsible for storing water, increasing skin volume and making skin look full, plump and elastic. However, hyaluronic acid will disappear with age, making the skin lose its water storage capacity, gradually becoming dull, aging and forming fine wrinkles.