Aim To investigate the structure and hemodynamics characteristics of carotid and vertebral artery by ultrasonography in patients with acute cerebral infarction (ACI). Methods Carotid artery and vertebral artery were detected by ultrasonography in 298 patients with ACI and 101 healthy controls. The differences of blood vessel diameter, intima-media thickness (IMT), vascular resistance index (RI) and blood flow velocity were analyzed between the two groups. According to the NIHSS score, the ACI group was divided into two subgroups:progressive ACI group and non-progressive ACI group. The differences of the above ultrasonic parameters were compared between the two subgroups. Results (1)Common carotid artery internal diameter, internal carotid artery internal diameter, common carotid artery RI, left internal carotid artery RI in ACI group were higher than those in healthy control group (P＜0.05). End diastolic velocity (Vd) of common carotid artery, peak systolic velocity (Vs) of internal carotid artery, internal carotid artery Vd, right vertebral artery Vs and Vd in ACI group were lower than those in healthy control group (P＜0.05). (2)Left common carotid artery Vs and RI, internal carotid artery IMT in progressive ACI group were higher than those in non-progressive ACI group (P＜0.05). Right vertebral artery Vs in progressive ACI group was lower than that in non-progressive ACI group (P＜0.05). (3)Pearson correlation analysis showed that age was correlated with various vascular ultrasonic parameters. Conclusions Carotid atherosclerosis vascular structural decompensation is one of ACI characteristics. IMT thickening of the internal carotid artery may be a risk signal of ACI progression.