Abstract: Objective 　To explore the clinical characteristics, diagnosis, treatment and prognosis of pulmonary carcinosarcoma ( PCS) . Methods 　Three cases with PCS were analysed ret rospectively in their clinicopathological data and light microscopic examinations. At the same time, reviewing literature job was done. Results 　The main symptoms of PCS were cough, expectoration, sometimes bloody phlegm. X-ray showed that the peripheral type were the most common type. Margin of the focuses were clear, leafy. The central type were companied by obst ructive pneumonia, atelectasis, and emphysema. The distensive lymph nodes of hilum or mediastium and metastases could also be seen. The 12year survival rate was 64. 4 % and the 52year survival rate was 26. 7 %. Conclusion 　PCS is not easy to distingnish with lung cancer, but the prognosis is better then lung cancer. Surgical resection is the main method of diagnosis and treatment .