Abstract: The article reports 4 cases with malignant fibrous histocytoma of the lung. This diseas is rare. The cases all had episodic blood-sneaking of the sputum. Direct extension of the tumous wasn't obvious according to the thoracotomy. The tumours all were given radical resection. Three cases among them died from metastasis in one year after operation. It had shown that this tumour has a malignant highly. Most or them have happened hematogenous spread before operation. The chemotherapy should be given early after operation.