To purpose of this study was to evaluate clinical results between rheumatoid arthritis shoulder cases and traumatic proximal humerus fracture cases. Fourteen patients who had been shoulder hemiarthroplasties between March 1991 to July 1996, six had rheumatoid arthritis and eight had comminuted proximal humerus fracture by the various trauma. Neer II prothesis were implanted in twenty cases and global prothesis were implanted in two cases. The follow up period was 15 months to 36 months. To evaluate this study, we used the UCLA shoulder rating. We were able to follow up thirteen cases for more than fifteen months, of which five cases had excellent, five cases had good, two cases had fair and one case had poor. And the results were better for patients with rheumaroid arthritis than for patients with trauma.