Acid gum is a kind of natural transparent polysaccharide, and it is a linear polymer polysaccharide with glucuronic acid -N- glucosamine acetate as disaccharide molecular unit. Originally used only for moisturizing, it has now been included in the ranks of wrinkle removal and plastic surgery. It exists in the dermis of human skin in the form of gel, which is responsible for storing water, increasing skin volume and making skin look full, plump and elastic.