Objective To investigate the relationship between C-reactive protein (CRP) and carotid intima-media thickness in pa-tients with impaired glucose tolerance (IGT). Methods Senan CRP was measured with immunoturhidimetry and the carotid intima-media thickness (CAIMT) was measured using color Doppler in 108 patients with impaired glucose tolerance (IGT) and 80 subjects with normal glucose tolerance(NGT).Then we observed all IGT patients for 3 years using prospective follow-up method, Oral Glucose tolerance test (OGGT) and every index were measured in follow-up 1.5 year and 3 year. Results 2 objects were lost to follow-up. IGT group showed a significant higher CAIMT and CRP compared with NGT group. After follow-up 1.5 year and 3 year, the patients with impaired glucose toler-ance (IGT) were divided into type 2 diabetes (T2DM) group and IGT group based on the level of blood glucose. Both T2DM group and IGT group showed a significant higher CAIMT and CRP, compared with NGT group. The level of serum CRP of T2DM group was higher than that of IGT group, and the level of serum CRP of IGT group was higher than that of NGT group. There were great differences between each group.Linear correlation showed that the level of blood glucose was positively correlated with CRP and CAIMT in T2DM group after follow-up 3 year. CAIMT was positively correlated with the level of blood glucose and CRP. Mulfivariant stepwise regression showed that CRP was signifi-canfly correlated with the level of blood glucose and CAIMT. Conclusion Inflammation played an important role in the development of dia-betes, and it had great vessels complication. The patients with impaired glucose tolerance, who have high level of CRP, were facilitated to be diabetes, and they were at risk of getting great vessels complication during the phase of impaired glucose tolerance. So it would be helpful to prevent IGT patients with high CRP or CAIMT with anti-inflammatory therapy.