Abstract: Objective To explore the correlation between the characteristics of carotid artery plaque and stenosis degree, and the severity of coronary atherosclerotic lesions.Methods Patients who underwent one-stop head,neck, and coronary computed tomography angiography (CTA) from July 2023 to September 2024 were included. According to carotid plaque characteristics (no plaque, stable plaque, and unstable plaque) and degree of stenosis (none, mild, and moderate or above), the patients were divided into different groups. Differences in coronary Leiden scores and branch vessel CT-derived fractional flow reserve (CT-FFR) were analyzed among groups. Statistical analysis was performed using the Kruskal-Wallis H test (with Bonferroni correction for multiple comparisons) and Spearman correlation analysis.Results Carotid plaque characteristics and stenosis degree were significantly correlated with coronary Leiden scores (P<0.001). Significant differences were observed as to CT-FFR values in the left anterior descending artery (LAD) and left circumflex artery (LCX) among the carotid plaque subgroups (P<0.05), while no significant difference was found in CT-FFR value of the right coronary artery (RCA) (P>0.05). Spearman analysis showed that the Leiden score and the CT-FFR values of LAD and LCX were significantly correlated with carotid plaque characteristics and degree of stenosis (|r|=0.285-0.672, P<0.05), with LAD CT-FFR showing the strongest correlation with carotid plaque characteristics (r=-0.472, P<0.001).Conclusions Patients with unstable carotid plaques and moderate-to-severe stenosis exhibit more severe coronary artery disease. Among CT-FFR measurements, LAD is more sensitive to carotid atherosclerosis, indicating that carotid plaque features may serve as imaging markers for risk stratification of coronary atherosclerosis.