Hyaluronic acid (HA) is an acidic mucopolysaccharide. With its unique molecular structure and physicochemical properties, it plays a variety of important physiological functions in the body, such as lubricating joints, regulating the permeability of blood vessel wall, regulating the diffusion and operation of proteins, water and electrolyte, and promoting wound healing. Most importantly, HYalURonic ACID (HA) has a special water-retaining effect and is the best moisturizing substance found in nature at present. It is called the ideal natural moisturizing factor. The efficacy and role of HYaluronic acid: 1. It has excellent affinity for water and can reorganize water inside tissues to better bear load or lubricate. 2. Folding occurs to form a three-dimensional network, resulting in physiological effects. It INCLUDES PRODUCING FLUID RESISTANCE, MAINTAINING WATER BALANCE AND INTERNAL environment STABILITY, AFFECTING THE SOLUBILITY, SPATIAL CONFIGURATION, CHEMICAL balance AND SYSTEM OSMOTIC PRESSURE of biological MACROmolecules, PREVENTING pathogen playback, and GUIDING THE deposition OF COLLAGEN fiber secretory SUBSTANCES. 3, it is connected with proteins that cannot be separated to form aggregates, which maintain the shape and volume of the tissue and ensure the reversible compressive resistance of the tissue. 4, it has certain effects on macrophages, mucocytes, lymphocytes and natural killer cells. 5. Hyaluronic acid (HA) is an important component of the interstitium, which is mainly degraded in the liver. When liver fibrosis occurs, HA synthesis increases, and the function of liver cirrhosis decreases, so the blood HA level increases abnormally. At present, evaluation of HA is a highly sensitive and specific index for the diagnosis of the degree of liver fibrosis and cirrhosis.