Abstract： Objective To investigate the relationship between serum leptin and carotid intima-media thickness in patients with type 2 diabetes mellitus. Methods 35 patients with type 2 diabetes mellitus (DM) and 16 normal controls were studied. Fasting serum leptin, fasting glucose(FBG), HbAlc, C-peptide, lipide, systolic(SBP), diastolic blood pressure(DBP), body mass index (BMI) and waist circ-umference (WC) were measured in all subjects. The intima-media thickness (IMT) of common carotid artery was measured by high-resolu-tion ultrasound imaging. Results IMT of T2DM was positively correlated with leptin concentration. Conclusion Serum leptin concentra-tion is independently associated with the IMT of carotid artery, which suggest that leptin may be an independent risk factor of atherosclerosis.