Post-thoracotomy pain is so severe that lead to postoperative pulmonary complications due to the patient`s inability to cough, deep breathing and chest wall motion. Many authors have been trying to reduce the post-thoracotomy pain, but there is no method of complete satisfaction. In 1990, we reported the result that the cryoanalgesia reduce the immediate postoperative pain significantly. We try to compare the effect of cyroanalgesia with the effect of Bupivacain intercostal nerve block for the post-thoracotomy pain control. Ninety patients, who undergoing thoracotomy in Korea University Medical Center Guro Hospital between the January 1993 and September 1993, were evaluated. The patients were divided into three groups : Group A, control, the patients without pain control procedure [N=30], Group B, the patients with Bupivacain intercostal nerve block [N=30], Group C, the patients with cryoanalgesia [N=30]. Postoperative analgesic effects were evaluated by the scoring system which made arbiturary by author. The results were that the Bupivacain intercostal nerve block markedly reduced the immediate postoperative pain compare with two other groups, the cryoanalgesia reduced the immediate postoperative pain significantly compare with control group, the pain reduction effect of the two groups- cryoanalgesia and Bupivacain intercostal nerve block- were not different at postoperative seventh day, probably due to the action time of Bupivacain and the result that there were no significant complications of the procedures.