PURPOSE: Proximal humerus fractures are relatively frequent and have variable treatment mothods. It is important to resolve union of the fracture site, good range of motion and function through the early ambulation in treatment results. We will know whether it is recommendable treatment or not and analyze the results of treatment on the effectiveness of the external fixator in two or three part fractures of the proximal humerus fractures. MATERIALS AND METHODS: From May, 1999 to April, 2001, 8 cases in 8 patients were treated by external fixator on the proximal humerus fractures. Mean age was 44.7yrs(11 to 68 yrs), two part fracture 6 cases, three part fracture 2 cases in fracture classification by Neer. We treated 3 cases with ring external fixator, 4 cases with monoplane external fixator. We referred chart and radiographics to patients and assessed the results by Neer 's shoulder function table through final follow-up or phone call. RESULTS: In all cases, we obtained bone union without neuroparalysis, neurovascular injury, avascular necrosis and other complications. Mean bone-union time was 7 weeks(5 to 12 weeks). Final functional assessments are excellent or good in 7 cases, poor in 1 case. CONCLUSION: We obtained comfortable results after we performed external fixation on proximal humerus fracture and bone union was acquired and removed external fixator at 7 weeks through early ambulation. We think procedure has brief, low soft tissue damage, high stability and motily. Thus we think it is recommendable treatment on the displaced proximal humerus fractures.