Abstract: Objective: To investigate the clinical value of 64 detector spiral CT angiography(CTA) in the diagnosis of moyamoya disease.Methods: The CT scan and CTA examination data of 16 cases with moyamoya disease were retrospectively analyzed.their imaging features were compared.Results: Cerebral hemorrhage in 8 cases.cerebral infarction in 2 cases.cerebral hemorrhage and infarction in 2 cases.and brain atrophy and cerebral hemorrhage in 2 cases were found,2 cases with no obvious abnormalities.The CTA showed that bilateral anterior and middle cerebral artery stenosis and occlusion in 4 cases and unilateral stenosis and occlusion in 3 cases.The different degree of stenosis and occlusion in bilateral internal carotid artery and C1.A1 or A1-A3 and M1 segment of anterior and middle cerebral artery of 9 cases were found.The merger of posterior cerebral artery stenosis in 3 cases and moyamoya in 16 cases were found.The large increasing and circuity and extending blood vessel in collateral vessels were showed.Conclusions: CTA is an efficient and practical technique in diagnosing moyamoya disease.which has great clinical value.