[Objective] To compare the clinical outcomes of locking plate with fibular strut allograft or with cancellous bone allograft for the treatment of proximal humeral fractures (Neer 3- or 4-part) in elderly patients. [Methods] A retrospective study was conducted on 66 elderly patients who received locking plate fixation for proximal humeral fractures in our hospital from January 2012 to December 2019. Among them, 31 patients underwent fixation with locking plate augmented by fibular allograft, while the remaining 35 underwent operation augmented by cancellous bone allograft. The two groups were compared regarding perioperative, follow-up, and radiographic data. [Results] All patients in both groups had surgical procedures finished successfully. There were no statistical differences between the two groups in operation time, intraoperative fluoroscopic frequency, blood loss, and length of hospital stay (P>0.05). The patients were followed up for at least 12 months. At 6 months and 12 months postoperatively, no significant differences were seen between the two groups in terms of the Constant-Murley score(CMS), American Shoulder and Elbow Surgeons(ASES) score, forward flexion range of motion, and abduction range of motion of the shoulder (P>0.05). The changes of neck-shaft angle (ΔNSA) and humeral head height (ΔHHH) were lower in the fibular allograft group than in the cancellous bone allograft group with significant differences (P<0.05). [Conclusion] The elderly patients with Neer 3- or 4-part proximal humeral fractures treated with locking plate combined with fibular allograft or cancellous bone allograft have similar good clinical outcomes, while the fibular strut allograft has a better ability to maintain the NSA and HHH.