Objective · To investigate the relationship between quantitative indices of carotid plaques from contrast-enhanced ultrasound and leukocytes, and explore the value in the patients with acute large artery atherosclerotic stroke (LAAS).  Methods · A total of 62 patients with LAAS and 48 matched control subjects hospitalized in Shanghai General Hospital, Shanghai Jiao Tong University from June 2016 to June 2017 were enrolled. Obvious carotid plaques were examined by contrast-enhanced ultrasound. The parameters of time-intensity curve i.e. peak (PTIC) and mean (MTIC), and the parameters of fitting curve i.e. peak (PFC), sharpness (SFC), and under the curve area (AUCFC) were obtained. These parameters were compared between the groups using two samples t tests. The correlations between the parameters and leukocyte counts were analyzed by Pearson correlation analysis.  Results · ① In LAAS group, the total leukocyte and neutrophil counts were higher than those of the control group, while the lymphocyte count was lower than that of the control group (P<0.05). ② The PTIC, MTIC, PFC, SFC and AUCFC were significantly larger in LAAS group than those in the control group, respectively (P<0.05). ③ PTIC, MTIC and PFC were negatively correlated with lymphocytes, respectively (r=-0.291, -0.263 and -0.270, P<0.05). SFC and AUCFC were positively correlated with neutrophils, respectively (r=0.261 and 0.298, P<0.05).  Conclusion · Quantitative indices of carotid plaques from contrast-enhanced ultrasound are associated with circulating leukocytes, and the association helps assess the vulnerability of the plaques.