Objective：To explore the relationship between hemoglobin glycation index（HGI）and carotid intima -media thickness （cIMT）in patients with type 2 diabetes mellitus（T2DM）. Methods：A total of 302 T2DM patients admitted to the Affiliated Yancheng Maternity and Child Health Hospital of Yangzhou University Medical School were enrolled. The clinical parameters including cIMT， fasting plasma glucose（FPG），and glycated hemoglobin A1c（HbA1c）were measured. HGI was calculated based on HbA1c and FPG， with high HGI defined as HGI ≥ 0 and low HGI defined as HGI < 0. The relationship between cIMT and HGI was observed. Results： Among the 302 patients with T2DM，140 cases（46.4%）had thickened cIMT. The proportion of high HGI in the cIMT thickening group was higher than that in the normal cIMT group（36.4% vs. 22.8%，P < 0.05）. The cIMT thickening group also had longer duration of diabetes，higher smoking rate，hypertension rate，systolic blood pressure（SBP），diastolic blood pressure（DBP），HbA1c，and low-density lipoprotein cholesterol（LDL-C）levels compared to the normal cIMT group（P < 0.05）. The estimated glomerular filtration rate （eGFR）was lower in the cIMT thickening group（P < 0.05）. HbA1c and HGI were positively correlated with cIMT（r=0.257，0.399，P < 0.05）. Logistic regression analysis showed that both HGI and HbA1c increased the risk of cIMT thickening［OR =1.511（95% CI： 1.237-1.846），OR=1.287（95% CI：1.053-1.571）］. Conclusion：The prevalence of atherosclerosis is high in patients with T2DM，and HGI may be a new indicator of atherosclerosis risk in T2DM patients，beyond HbA1c.