The shoulder fusion has been performed to relieve pain, eradicate infection, improve the function and stabilize the flail shoulder joint. Thirteen shoulders were fused from Dec. 1981 to June 1989 at Department of Orthopedic Surgery of Seoul National University for treatment of various conditions including brachial plexus injury, tuberculosis of shoulder and residual poliomyelitis. The results were analyzed with particular reference to the relationship of fusion angle and the function. The average period of follow-up is about 2 years. The average angle of shoulder fusion was 44 degrees of abduction(31°-63°), 21 degrees of flexion of the arm(12°-35°) and 26 degrees of internal rotation(19°-37°) The results were assessed based on pain, function, satisfactory response and ability to resume the previous job. Overall satisfacotry results were obtained in 9 of 13 shoulders. In brachial plexus injury, the result was worse than that in other diseases due to wide neurologic involvement. We obtained the more satisfactry result when the shoulder is in the position of abduction 30°-40°, flexion 15°-25°and internal rotation 15°-30°. The muscle power of trapezius and serratus anterior play an important role in obtaining the better result. In conclusion, proper patient selection, fusion angle, and muscle power were important prognostic factors.