Abstract: Objective To investigate the relationship between blood glucose fluctuations and carotid intima-media thickness (CIMT) in type 2 diabetic patients. Methods 64 patients with type 2 diabetes mellitus (T2DM) in the Department of Endocrinology and Metabolism, West China Hospital from July 2009 to March 2012 were recruited in this study. The CIMT were measured bilaterally with high-resolution ultrasonography. The glucose excursions were assessed by the following parameters obtained from the continuous glucose monitoring system (CGMS) for 72 h:mean blood glucose (MBG) and its standard deviation (SD), mean amplitude of glycemic excursion (MAGE), mean of daily differences (MODD). Glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c) of the participants were also determined. According to the levels of CIMT, 64 diabetic patients were classified into two groups:diabetes mellitus without atherosclerosis (A group, n=37) and diabetes mellitus with atherosclerosis (B group, n=27). The relationship between the parameters of glycaemic variability and CIMT was examined. Results ①There were no differences between A group and B group with regard to gender composition, course of diabetes, body mass index (BMI), diabetic chronic complications, family history of diabetes, smoking, alcohol drinking, diastolic blood pressure (DBP), TG, TC, HDL-c, SD and MAGE (P>0.05). A group had younger age and lower levels of systolic blood pressure (SBP), LN(LDL-c) and LN (MODD) than B group (P<0.05). ②Pearson correlation analyses showed that CIMT was positively correlated with age (r=0.370, P=0.005), LN(LDL-c) (r=0.325, P=0.009), SD (r=0.251, P=0.045) and LN (MODD) (r=0.346, P=CM(154.5mm0.005).③Age, smoking, LN(LDL-c) and LN (MODD) were identified as predictors for CIMT in the multiple linear regression analysis. Conclusion Glucose excursions may contribute to the development of atherosclerosis in patients with type 2 diabetes, which is independent from HbA1c levels.