Abstract: Objective Proximal humerus fracture is prone to rotator cuff injury in different degrees. Severe rotator cuff injury is a common cause of limited shoulder movement after proximal humeral fracture surgery. The purpose of this study was to investigate the correlation between proximal humeral fractures with rotator cuff injury and Neer classification and age distribution of fractures. Methods A self-designed questionnaire was used to retrospectively analyze the clinical data of 126 patients with proximal humeral fractures who underwent surgical treatment from January 2012 to December 2016 in a third-class hospital in Haikou City. The incidence of rotator cuff injury in proximal humeral fractures with different Neer classification and age stratification was compared. Results There was no significant difference in age and type of proximal humeral fracture between different genders (χ²=0.030, P=0.985). Among 126 cases of proximal humeral fractures, 49 cases(38.9%, 49/126) were confirmed to have rotator cuff injury during operation, of which 41 cases were confirmed by MRI before operation. The average age of the patients with proximal humeral fracture combined with rotator cuff injury (76.9±9.8) was significantly different from that of the patients without rotator cuff injury (53.4±8.3, t=3.178, P=0.034). Neer classification of proximal humeral fractures had the highest incidence of rotator cuff injury in three-part fractures, accounting for 49.3% (37/67). Conclusion The proportion of patients with proximal humerus fracture combined with rotator cuff injury increases with age. Neer classification of proximal humerus fracture often combined with rotator cuff injury, which has guiding significance for clinical treatment of proximal humerus fracture.