To assess significance of surgical therapy for patients who had metastatic bone tumor from primary lung cancer, sites of recurrence in patients who underwent surgical resection for lung cancer lesions were analyzed. Clinical courses of patients who underwent surgical therapy for metastatic bone tumor were analyzed, too. 1) From 1985 to 1989, 88 patients died from lung cancer in our hospital who has underwent pulmonary resection for lung cancer lesions. Of these, 22 patients had metastatic bone tumor. Sixty patients died who had underwent complete resection for lung cancer lesions. In eight patients of these 60 cases, bone were first site of recurrence. Of these eight patients, length from pulmonary resection to detection of bone metastasis were 4-23 months. In the other hand, length from detection of bone metastasis of death were 3-24 months. There was no correlation between two length. All of these eight patients had another metastatic lesions at the time of death. 2) From 1985 to July 1993, twelve patients underwent surgical therapy for their bone metastasis of primary lung cancer. Of these, four had metastatic cancer in thoracic vertebral body, two had in clavicle, two had in rib, three had in femoral bone, another had in tibial bone. Objective of operation were improvement of paralysis or pain, prevention of fracture, and so on. Most cases succeeded to get improvement in a short time, but some cases got worse soon. Surgical treatment was effective to improve paralysis or pain, and to increase quality of life. But it can not be effective except appropriate management in a short time because another symptom raise soon.