Aim: To study the relation between multiple factors of vascular lesion and the decrease of regional cerebral blood flow (rCBF) at the interval of transient ischemic attact (TIA). Methods: Fifty-six TIA patients hospitalized in the Department of Neurology, Xuanwu Hospital from June 2001 to July 2002 were examined by single photon emission computerized tomography(SPECT), transcranial Doppler(TCD) and color-coded Doppler sonography(CCDS), and correlation analysis was done. Results: The order of vascular factors related to TIA was cerebral atherosclerosis(73.3%), carotid artery plaque number(69.2%), carotid artery plaque which was easily shed(23.2%) and intracranial or extracranial vascular stenosis(19.0%). There was significant difference between the elders and non-elders for these factors, with a pattern of closer relation for the former. Conclusion: The major factors of TIA are atherosclerosis, intracranial or extracranial vascular stenosis, and number and quality of carotid artery plaque. Incidence of intracranial atherosclerosis and vascular stenosis is higher than that of extracranial atherosclerosis and vascular stenosis.