Objective To investigate the changes of inflammation levels in patients with impaired glucose tolerance(IGT) and the clinical significance.Methods A total of 30 IGT patients(IGT group) and 30 type 2 diabetes (T2DM) patients (T2DM group) were enrolled in current study.Meanwhile,30 health people were selected as control group (NGT group).The concentration of fasting plasma glucose (FPG),insulin resistance index (HOMA-IR),glycosylated hemoglobin (HbA1c),high-sensitivity C-reactive protein (hsCRP),cystatin C(Cys C) and fibrinogen(FIB) were measured.Results The levels of FPG,2 h glucose(2 h PG),HOMA-IR and HbA1c in three groups were significant (F =8.805,14.403,7.389,10.246 ; P ＜ 0.05).The levels of CRP,Cys C and FIB in three group were also significant (F =6.766,4.733,11.683 ;P ＜ 0.05).The levels of CRP,Cys C,FIB in IGT were (1.12 ±0.22) mg/L,(0.23 ±0.10) mg/L,(0.93 ±0.18) mg/L,higher than that in NGT group((0.70 ±0.16) mg/L,(6.02 ±0.49) g/L and (4.36 ±0.30) g/L).Meanwhile,the levels of CRP,Cys C and FIB in T2DM were significantly higher than of NGT(P ＜ 0.05).Single factor correlation analysis showed that there was positive associationship between hs-CRP,Cys C and FIB with 2 h PG,HbA1 c and HOMA-IR(P ＜ 0.05).Conclusion Endothelial dysfunction is seen in prediabetes stage,which plays an important role in the occurrence and development of vascular disease in impaired glucose regulation and diabetic patients.