Objective To explore the value of E-Tracking technique in evaluating the vascular endothelial function of carotid artery in subclinical hypothyroidism.Methods The study population include 38 subclinical hypothyroidism patients and 60 normal controls.E-Tracking technique was performed to track the movements of the common carotid artery and the following parameters were assessed:stiffness parameter(β),elastic coefficient (Ep),arterial compliance (AC),augment index (AI) and one point pulse wave velocity (PWVβ).Results Ep,β,AI and PWVβ were significantly higher in subclinical hypothyroidism than those in the control group,AC were lower than that in the control group( P ＜0.05).Conclusions Vascular endothelial function in subclinical hypothyroidism patients is injured in early stage.ETracking technique may conduce to find the injury early and may assess it quantitatively.