Objective: To analyze the preoperative pulmonary function in rotator cuff injury patients and the possible influencing factors. Methods: All the rotator cuff surgery patients who underwent pre-operative pulmonary function examination in Peking University Third Hospital from Jan. 2020 to Jun. 2020 were retrospectively reviewed. Their perioperative medical records and main parameters of pulmonary function were collected from database management system, and their gender, age, body mass index (BMI), smoking history, time from injury, visual analogue scale (VAS) and other factors impacting on preoperative pulmonary function were studied. Results: Twenty-nine patients with rotator cuff injury were included, among whom 1 patient was reported to have restrictive ventilation dysfunction and 2 patients to have obstructive ventilation dysfunction. All the three patients denied the history of respiratory diseases, and had no respiratory symptoms. In all enrolled patients, the mean forced expiratory volume in one second (FEV1)/ forced vital capacity (FVC) was 79.2%±5.9%, and the mean VAS pain score was 3.66±1.26. In addition, the dynamic pulmonary functions (FVC, FEV1) were reduced in more than half of the elderly, and the total lung capacity (TLC) was lower than the estimated value in 2/3 of the elderly. There were significant differences in three main indexes of pulmonary functions between genders, and the percentage of the estimated TLC between normal BMI group (18 kg/m²<24 kg/m²) and overweight/obesity group (BMI≥24 kg/m²) was significantly different. Based on the injury time longer than 1 year or not, the results indicated that FVC and TLC were significantly different between the two groups. Conclusion: In addition to gender and age, time from injury and severity of pain, as well as overweight/obesity, may influence pulmonary function outcomes in the elderly rotator cuff patients. Targeted intervention can be carried out on these factors before surgery. Preoperative lung function test can be used as one of the basic evaluation indexes for respiratory training and rehabilitation of patients.