Lobectomy and systemic mediastinal lymph node dissection are the standard procedures for operable non-small cell lung cancer. From January 2003 to March 2005, a total of 40 cases of total pneumonectomy were performed in our hospital, including 5 cases of partial resection of the left atrium. There were 17 cases of squamous carcinoma, 8 cases of adenocarcinoma, 10 cases of small cell undifferentiated carcinoma, and 5 cases of adenosquamous carcinoma. There were no perioperative deaths, and the survival rates were 65% (26/40), 37.5% (15/40), and 17.5% (7/40) at 1, 3, and 5 years after surgery, respectively, with one case of small cell lung cancer surviving more than 6 years. Arrhythmias after total pneumonectomy, mostly supraventricular tachycardia or atrial fibrillation, occur mostly within 2 days after surgery, and their causes may be related to poor postoperative sputum evacuation, residual lung inflammation, vagal nerve stimulation, postoperative pulmonary hypertension, electrolyte disturbances, etc. Because of the complex etiology, there is no one completely reliable preventive measure. We have experienced that the type of postoperative rehydration is mainly colloid and limiting the amount of crystalloid can avoid residual pulmonary edema, reduce airway secretion and fine bronchospasm; pay attention to respiratory management, strengthen nebulized inhalation, and diuretic as appropriate, so as to improve ventilation and ventilation function and reduce the occurrence of hypoxemia, and supplement electrolytes with special attention to magnesium ions. In case of arrhythmia, intravenous injection of Sidilan, cardioplegia, Kadolone and other drugs can be administered according to the condition, which can often be converted to sinus rhythm within 24h. When the tumor invades part of the left atrium wall, our experience is to remove as little normal atrial tissue as possible, and if necessary, try to clamp the left atrium to be removed first, if there is no change in blood pressure, heart rate and terminal oxygen saturation after 5 seconds, then it can be removed, otherwise it should be abandoned. The method of suturing the left atrial cut edge varies, but our group all used the distal line of the cardiac ear clamp for continuous suturing, which has the advantage of less bleeding and firm suturing. In conclusion, total and partial left atrial resection via intrapericardium can improve the surgical resection rate of intermediate and advanced lung cancer. It reduces the risk of intraoperative hemorrhage and creates conditions for further treatment of intermediate and advanced lung cancer, which is an effective procedure worth trying for the treatment of intermediate and advanced lung cancer.