OBJECTIVE To review the physiological function of sodium hyaluronate in joints and its clinical applications. METHODS Many literatures were reviewed and analysed on therapeutic mechanism and the application foreground of sodium hyaluronate. RESULTS Extrinsic sodium hyaluronate plays an important role in improving synovial fluid and protecting cartilages as well as suppressing inflammation, so it is used in the treatment of joint diseases such as knee osteoarthritis, rheumatoid arthritis or temporomandibular osteoarthritis. CONCLUSION Sodium hyaluronate possesses a good applied prospect in joint diseases.