OBJECTIVE To observe the effects of sodium hyaluronate on nerve root adhesion after operation of lumbar disc protrusion (LDP). METHODS From April 1996 to June 2001, 152 cases with LDP were performed the removal of nucleus pulposus under endoscope. After operation, 2 ml of sodium hyaluronate were injected. The clinical results were evaluated by clinical symptom, straight leg raising test, patient’s satisfaction degree and back pain. RESULTS All the patients were followed for 1 month to 3 years. The average angle of straight leg raising test increased from 26 degree preoperatively to 62 degree postoperatively. The patient’s pain were markedly relieved. Patient’s satisfactory degree were 86.8%. CONCLUSION The injection of sodium hyaluronate after operation of LDP has effect on preventing postoperative nerve root adhesion.