A carotid plaque of 1.7 mm (millimeters) is not necessarily serious, but it still needs to be taken seriously, in addition to its degree of stability. Carotid ultrasonography measures the plaque and expresses the size in terms of length (mm) x thickness (mm). The carotid arteries include the common carotid artery, internal carotid artery, and external carotid artery, and the lumen of different arteries varies in thickness. The normal internal diameter of the common carotid artery is about 6-7.5 mm, while that of the internal carotid artery is 5-6 mm and that of the external carotid artery is 4.5-5.5 mm. Carotid plaque of 1.7mm in either of these carotid arteries is a mild stenosis and does not cause significant hemodynamic effects. However, carotid plaque may continue to increase in size and progress, causing narrowing of the vessel lumen and occlusion. If the plaque is equal or mixed echoes rather than strong echoes, it means that the composition of the plaque is skewed towards non-calcified plaque, which is less stable. It can easily lead to rupture or dislodgement resulting in complications such as embolism, which is more serious. Carotid plaque 1.7mm still need to pay attention to, need to timely consultation, standardized treatment.