Pneumothorax, a frequently encountered disease in the clinic, has been interesting to surgeons for it`s high recurrence rate. 52 patients with a second attack of pneumothorax at our hospital in a 24 month period were evaluated especially for the risk factors of recurrence. The results were as follows:1. Patients after operative treatment[21 cases There were no postoperative complications and recurrence.2. Patients with tube drainage or conservative treatment [31 cases [i Overall recurrence rate was 45.2 %. [ii Suggestive risk factors for the recurrence were: age above 30 years, short period of thoracostomy less than six days. And other factors such as male, right lung, higher level of lung collapse were thought to be followed further more.