Objective: To evaluate the hemodynamic characteristics of severe carotid artery stenosis and curative effect of stent angioplasty through XeCT. Methods: From April 2006 to November 2006, 13 patients with severe carotid artery stenoses underwent stent angioplasty in our hospital, including 11 male and 2 females, in an average age of 57.31 ± 6.12. All patients underwent XeCT examination to evaluate the quantitative cerebral blood flow (CBF). The ischemic cortex is categorized into 4 kinds, the normal region, oligemia area, reversible ischemic site and ischemic core center. Measurement and comparison of the changes were taken before and after the therapy. Results: Preoperative XeCT revealed different decrease of CBF in the ipsilateral cortex, especially in MCA distributing territory. Ischemic areas reduced significantly after the stenting angioplasty. Oligemia area reduced from 32.63% to 14.22%. Reversible ischemic area reduced from 13.54% to 8.38%. Normal area increased from 47.51% to 71.13%. But ischemic core center showed no significant changes. Conclusions: XeCT is beneficial for evaluation of the hemodynamic characteristics of carotid artery stenoses and also for accurately demonstrating the curative effects of the stent angioplasty.