Carcinosarcoma is an unusual and rarest neoplasm in man, consisting of carcinomatous parenchyme and sarcomatous stroma. Two clinical types of carcinosarcoma were present. One type of tumor was centrally located [endobronchial type], infrequent metastasis, and better prognosis than parenchymal type. The other type was peripherally located [parenchymal type], frequent metastasis, and poor prognosis. The histogenesis of carcinosarcoma is many hypothesis, but controversial; 1] sarcomatous degeneration of stroma, 2] intermingling of simultaneously arising carcinoma & sarcoma, 3] multiple primary tumor, 4] blastomatous changes in hamartoma, 5] stromal reaction to squamous cell carcinoma, 6] true & collision carcinosarcoma. In this case, 52 year-old male patient was hospitalized due to intermittent hemoptysis & known pulmonary lesions. Since 1968, chest PA showed round haziness within cyst & multiple cyst on RUL & RLL. Radical pneumonectomy was performed and histopathology showed carcinosarcoma, surrounded by bronchial epithelium. The patient maintain general well-being without clinical evidence of recurrence till now.