Lung careinosarcoma is a rare pulmonary mixed malignant tumor. From November 1979 to Sept. 1992, among 4,251 eases of pulmonary malignant tumor operated in our department 15 were lung carcinosarcoma (0.35%). Pneumonectomy was done in 6 patients, Iobectomy in 8, thoracotomy in I. Pathologically, squamous carcinoma with fibrosarcoma in I, adenocarcinoma with fibrosarcoma in 7, adenocarcinoma with chondrosarcoma in I, and small-cell carcinoma with chondrosarcoma in 1. There was no operation death. Upon follow up, the 1-, 3-, 5-, and 7- year survival rates were 66.7%, 53.3%, 42.9% and 2/7, respectively. The longest survival was 97 months. The histologica origin, the relationship between pathological findings and clinical features and the diagnosis, treatment and prognosis are discussed.