In recent years, with the aging of the population the incidence of cardiovascular disease has increased significantly and has become one of the high incidence, its basic cause is atherosclerosis, carotid ultrasonography can be used as an independent factor to predict the disease, research has proved that, in addition to hyperlipidemia, hypertension, smoking, hyperinsulinemia and diabetes, age is also one of the important risk factors for the development of carotid atherosclerosis, that is, with the age As we age, a series of age-related changes occur in the carotid arteries, leading to a decrease in arterial elasticity and buffering capacity, which promotes the development of atherosclerosis. First, aging can cause a progressive decline in arterial compliance, with a compensatory increase in vessel diameter that limits the decline in compliance. It has been demonstrated that the internal diameter of carotid artery increases significantly in those aged >60 years. Under the condition of relatively uniform blood flow, the blood flow velocity is generally inversely proportional to the flow surface (diameter), and the internal diameter of carotid artery increases with age while the blood flow velocity gradually decreases, which is especially obvious at the age >50 years. Pathologically, the early lesions include intimal rupture, platelet aggregation, vasoconstriction and migration of smooth muscle cells from the middle layer of the artery to the inner layer of the vessel, and the flow of lipoproteins from the intimal rupture into the subintimal interstitium to form a buildup, resulting in thickening of the intima-media thickness (IMT). According to the physical properties of ultrasound, the image produced when the beam enters the higher density tissue from the lower density tissue is consistent with the anatomical location of this interface, and the measurement of IMT in the posterior carotid wall is relatively reliable. The incidence of atherosclerosis increases with age, indicating that the deposition of lipids, the increase of necrotic tissue and collagen and elastic fibers produced in the plaque lesion lead to the development of atherosclerosis in the middle and late stages, and the increasing extent of atherosclerotic lesions. According to Newton’s law of viscosity, the shear stress is proportional to the SR, so the level of SR reflects the magnitude of the shear stress, which is the frictional force on the endothelial cells of the arterial wall caused by the periodic pulsating flow of blood in the artery with the elastic arterial wall as the boundary. It is the most closely related mechanical factor to atherosclerosis. Some studies have shown that the shear stress in normal carotid arteries decreases with age, and low shear stress induces the occurrence of atherosclerosis because the blood flow is slow, monocytes, lymphocytes and serum lipoproteins are easily deposited here, and the clearance of lipoproteins is reduced. Low levels of shear stress can cause damage to the endothelium, resulting in monocytes adhering to the endothelium and moving to the submucosa, forming lipid streaks where platelets accumulate, leading to atherosclerosis. It has been proved that carotid arteries of people over 50 years old have different degrees of IMT thickening, SR decrease and the corresponding increase of plaque incidence is an indication that carotid arteries gradually become atherosclerotic with age, and the degree of atherosclerosis is directly proportional to age. In summary, we believe that there is a strong independent correlation between ageing and carotid atherosclerosis, and dynamic observation can help early detection of normal individuals, especially those >50 years old, who should have regular carotid ultrasound examinations. 2D color Doppler ultrasound (2DCDUS) can easily and accurately detect carotid arteries and provide an important basis for prevention and treatment of atherosclerosis. At the same time, comparative pathological studies have proved that the thickness of the arterial wall determined by ultrasound is much more accurate than that of angiography, so the use of non-invasive means of ultrasound can not only observe and understand carotid atherosclerotic lesions and their extent in a timely manner, but also provide a reliable basis for clinical diagnosis and treatment, which is of great clinical significance for the prevention of cardiovascular and cerebrovascular lesions.