Abstract: Objective To study the relationship between the image manifestation of bronchial arteriograghy (BAG) and pathologic mechanism,and quest reliable basis for its diagnosis and bleed locating.Methods 1 52 patients with cryptogenic hemoptysis were selected,including following two group:①routine image examinations (including chest plain film,tomogram,computed tomography and bronchialgraphy) were negative.②one lobe or segment showed a few lesions,but they were not the ones for causing hemoptysis proved by BAG,while another lobe or segment had signs of bleeding (17 cases).All these patients were performed by seldnger puncture technique,and catheter was put through aorta into bronchial artery.If bronchial arteriography showed direct or indirect bleeding signs,bronchial arterial embolization (BAE) was performed.2 Another 5 cases with bronchial lesions were selected,which were demonstrated by preoperative image examinations and confirmed through BAG procedures to be bleeding cause and location.They were given surgical operation because BAE were ineffective or there were other lesions.Pathological examination under microscope were conducted on these operation samples,and the correlation between BAG findings and phthologic changes was analyzed.Results For all patients with hemoptysis,their BAG showed different degree of hypervascularity,typically being broomlike or reticulate proliferation and deranging vascular bundles.Serious cases were accompanied by intrapulmonary bleeding focus.Combined the BAG findings with pathological findings from the operation samples of patients with bronchialectasis,both blood vesseles changes were identical.Conclusion 1 Pathological mechanism of cryptogenic hemoptysis is the damage of bronchial artery,which are caused by infection of bronchial artery,therefore blood vessel abnormalities indicated by BAG may provide the basis of diagnosis and bleeding locating for cryptogenic hemoptysis.2 Bronchial arteriography and embolization can integrate diagnosis with therapy,which is safte and effective,and the patients have small injuries.There is practice significance in saving the patients with massive hemoptysis.Bronchial arteriography and embolization can provide a new and effective method for controlling massive hemoptysis.