Microfil perfusion technique was used to investigate the blood supply of bronchogenic carcinoma deriving from pulmonary artery on 20 fresh specimens of lung cancer, including 11 squamous carcinoma, 6 adenocarcinoma, 1 alveolar cell carcinoma and 2 undifferentiated carcinoma cases. The results showed that the appearance and quantity of pulmonary blood supply of bronchogenic carcinoma depended on and changed with the site, activity, growth mode as well as the local condition of tumor nodules; pulmonary artery supplied blood to the periphery of the tumor and its innermost part as well; vessels from pulmonary artery in tumor nodules were generally less in number than those in the surrounding normal lung tissues around. The results suggested that the tumor blood supply from pulmonary artery Should be evaluated comprehensively and dynamically; during interventional chemotherapy via pulmonary artery, patients should be selected carefully and the catheter for infusion placed in suitable position so as to gain the best therapeutic effect.