Twenty-five patients who underwent upper sleeve lobectomy for lung cancer were studied by spirometric examination to evaluate postoperative pulmonary function, including Vital Capacity (VC), %Vital Capacity (%VC), Forced Expiratory Volume in one second (FEV1.0), and Forced Expiratory Volume in one second as a percentage of the forced vital capacity (FEV1.0%). The results of the patients with bronchoplasty were compared with those of patients with lobectomy alone and of patients with pneumonectomy. Lung function was periodically examined postoperatively following bronchoplasty. VC, %VC and FEV1.0 were decreased postoperatively in the patients with upper sleeve lobectomy, while FEV1.0% was increased. There were no differences in postoperative %VC or FEV1.0% between the patients with bronchoplasty and those with upper lobectomy alone. However, the postoperative %VC of the patients with pneumonectomy was significantly decreased compared with patients who underwent postoperative %VC of the patients with pneumonectomy was significantly decreased compared with patients who underwent bronchoplasty or lobectomy alone. %VC in the patients with bronchoplasty was decreased at 3 months after operation, but it to gradually returned to the preoperative value by 13 to 24 months after operation.