Objective:To explore the features of atherosclerotic plaque in patients with type 2 diabetes mellitus by contrast-enhanced ultrasound (CEUS), and to analyze the correlation between the features and leukocyte count in peripheral blood.Methods:A total of 30 type 2 diabetic patients with carotid atherosclerotic plaque treated in Tangdu Hospital of Air Force Military Medical University who underwent CEUS from March 2018 to September 2021 were included as the diabetes group. Thirty-two non-diabetic patients with carotid atherosclerotic plaque who were matched for age and sex during the same period served as the control group. The optimized plaques were performed by CEUS to obtain parameters including peak (P), time to peak (TP), sharpness (S) and area under the curve (AUC) of time-intensity gamma fitting curve (FC curve). The differential count of leukocytes in peripheral blood was detected by the automatic hematology analyzer. Spearman rank correlation and multiple linear regression were used to analyze the correlation between CEUS parameters of plaque and the differential leukocyte count in peripheral blood.Results:①The peripheral blood leukocyte count, monocyte count and monocyte proportion in the diabetes group were higher than those in the control group (all P<0.05). ②P and AUC in the diabetes group were higher than those in the control group (all P<0.05). ③There was linear relationship( B=75.440, P<0.001) and positive correlation ( rs=0.929) between P and peripheral blood monocyte count in the diabetes group. Conclusions:The neovascularization density and perfusion in carotid plaques in patients with type 2 diabetes mellitus are increased, which may be related to the increase of leukocytes in circulation, especially monocytes.