The authors reviewed serial chest films of 113 patients of spontanesou pneumothorax which were treated by closed tube thoracotomy during the period from May, 1979 till July, 1982 in CNUH. The results are as follows 1. Male was more frequently affected than female, and the sex ration was 3.5 : 1. 2. 71.1 percent of patients were over 31 years of age. 3. Of the 113 cases, 51.3 percent were on the right, 48.7 percent on the left. 4. The most common underlying pulmonary disease was pulmonary tuberculosis (39.8), the next was belb or bulla (17.7%), and the last was pneumonia (8.8%). No disease evident case was 31.9 percent. 5. Pneumothorax was the most common type in pulmonary tuberculosis (66.7%), and pyopneumothorax in pneumonia (80.0%). 6. Among 103 cases in complete re-expansion of collapsed lung after closed the thoracotomy, 39.5 percent was expanded completely within 1 week in presence of visceral and/or parietal pleural thickening, and 86.2 percent in none of it. According to the degree of pneumothorax, the more severe degree of pneumothorax, the more delay in re-expansion times. 7. Most common chest finding after re-expansion of collapsed lung was pleural thickening (51.4%).