Objective To explore the value of color Doppler ultrasonography(CDU)as preoperative diagnosing and postoperative monitoring in patients with stenosis of subclavian or innominate artery(SIA)before and after percutaneous transluminal angioplasty and stent(PTAS).Methods A total of 45 patients with stenosis of SIA were selected.Their extracranial vertebral artery and subclavian artery were observed with CDU.In 36 patients with one-sided stenosis of SIA.blood flow direction and spectrum of extracranial vertebraI artery were analyzed.Subclavian steal grade confirmed by spectrum change of vertebral artery was compared with the stenosis grade on quantitative angiography(QA).Among 45 patients with stenosis of SIA,PTAS was performed successfully in 36 patients(36 stents implanted).After stents implanted, hemodynamie parameters such as peak systolic velocity(PSV)in stent, follow-up velocity ratio in stem(VR)were measured.Restenosis in stent were observed.Results In 36 patients with one-sided stenosis of SIA,the ultrasonographic steal grade correlated with the QA stenosis grade significantly(r=0.752,P<0.01).Among 36 patients with stent implanted,follow up 8-12 months, 4 patients with restenosis in stent were found.Compared with the patients without restenosis in stent,PSV and VR in stent increased significantly(P<0.01).Conclusions As a fast and non-invasive imaging technique,CDU could allow diagnosis of stenosis of SIA before PTAS,and detection of restenosis after PTAS.