In 1963, Suzuki ectc described in multiple progressive intracranial arterial occlusion and named "MoyaMoya" disease. Many cases of Moya Moya disease had been reported and discussed by some Japanses Authors and they asserted that Moya Moya disease is characterized by the intracranial congenital or developmental anomaly apparently confined to Japanese. But more recently, this diseases have been reported by some non-Japanese Authors,in the United States, Europe and Korea. We have experienced 6 cases of cerebrovascular Moya Moya disease from August 1976 to March 1979. We were proved by carotid and vertebral angiogram and clinical assessment. The resultsare as follows; 1. Age distribution was ranged from 7 to 41. Age under 20 were 4 cases and 4 cases were male and 2 females. 2. There were no contributory factors to cerebrovascular Moya Moya disease with regard to femilial background. 3. Clinical manifestations were mainly headache, vomiting, convulsion, hemiparesis and visual disturbance. 4. Angiographic findings reveal occlusion or stenosis of internal carotid artery at the supraclinoid portion inall cases except for on (petrosal region) and also abnormal fine vascular network, poor or non-visualization ofAnterior and Middle Cerebral Artery but relatively normal opacification of posterior cerebral artery. 5. Amongthese 6 cases, there was no evidence of subarachnoid hemorrhage or aneurysm on cerebral angiography.