Objective To explore the changes of hemodynamic after carotid angioplasty and stenting ( CAS) in patients with carotid artery stenosis .Methods Thirty-one carotid artery stenosis patients were treated with CAS , and were examined by color Doppler flow imaging ( CDFI) before operation and 1 d,3 months,one year after operation . Compared the carotid artery diameter , peak flow velocity (PSV) and end-diastolic velocity (EDV) before and after the operation.Results Compared with before operation , carotid artery diameter were significantly increased ,PSV, EDV were significantly decreased at each time point after operation ( all P<0.01 ) .Compared with 1 d after operation, there was no statistical difference on the CDFI results of carotid artery in 3 months after operation;compared with 1 d after operation the carotid artery diameter was significanty decreased in one year after operation ( P<0.05 ) , there was no statistical difference in PSV and EDV .Conclusions CAS can alleviate the carotid stenosis and improve the indicator of hemodynamics significantly .Vascular restenosis is found in some patients one year after operation , but there was no statistical difference in the indicator of hemodynamic .