Left upper lung resection usually affects cardiopulmonary function in the early stages and the body can compensate for it after recovery. Left upper lung resection is a kind of lung surgery, its function is to remove the lung tissue necrosis, or lung tumor and other diseased lung tissue, so as to achieve the therapeutic effect. Lung lobectomy will have a certain impact on the lungs, causing lung function to decline thereby affecting cardiopulmonary function, and patients will also experience symptoms such as chest tightness and shortness of breath. Patients should exercise to improve breathing and appetite after lobectomy, and also to prevent pulmonary complications and venous thrombosis of the lower extremities. They should also prevent colds and flu to avoid upper respiratory tract infections such as pneumonia and bronchitis. After the operation, patients should eat more high protein and vitamin-rich foods to strengthen the body’s resistance. It is recommended that patients follow the doctor’s instructions and go to the hospital regularly for review after the operation.