Abstract: Objective: To explore the value of color Doppler ultrasound in the diagnosis of carotid atherosclerosis of patients with cerebral infarction.Methods: The medial membrane thickness of carotid artery and plaque formation in 123 cases with cerebral infarction and 90 healthy people were analyzed.Results: The detection rates of carotid atherosclerosis plaque formation and pure intima thickening in the patients with cerebral infarction were 63.4% and 21.9%,respectively,the detection rate of plaque formation in more than 55 years old patients was significantly higher than that in less than 55 years old patients(P<0.05).The detection rates of carotid atherosclerosis plaque formation and pure intima thickening in healthy people were 6.7% and 11.1%,respectively.The detection rate of carotid atherosclerosis in patients with cerebral infarction was higher than that in healthy people(P<0.01).The detection rates of carotid atherosclerosis plaque formation in patients with cerebral infarction complicated with hypertension,diabetes and above two kinds of diseases were 72.6%,60.0% and 84.4%,respectively,which was significantly higher than that in cerebral infarction patients without hypertension and diabetes(P<0.01).Conclusions: Color Doppler ultrasound examination can early detect the carotid atherosclerosis in patients with cerebral infarction,which is a noninvasive and valuable method.The less than 55 years old of patient is a critical period.