We analyzed the cerebral arterio-venous circulation time of 141 cases of cranial DSA in 136 patients, for the assessment of cerebral circulatory dynamics. IV-DSA was 111 cases, IA-DSA 30 cases. The results were as follows : 1. There was no significant difference in arterio-venous circulation time between IA-DSA and IV-DSA, if the disease pattern was not considered(P> 0.1). 2. Prolongation of arterio-venous circulation time was noted in the cases of cerebral (cerebellar )hemorrhage, subarachnoid hemorrhage, intracranial hematoma, brain abscess, acute stage of cerebro-vascular occlusive disease, acute stage of postoperative follow up, and acute stage of cerebral contusion(P>0.05). 3. Compared the chronic stage of cerebro-vascular occlusive disease, postoperative follow up and cerebral contrusion with scute stage , significant decrement of arterio-venous circulation time was resulted(P>0.05). 4. DSA was a useful modality for the assessment of circulatory dynamics , including measu ement of arterio-venous circulation time.