Abstract: Objective: To investigate the changes of plasma homocysteine（Hcy） and serum C reactive protein（CRP） levels in subjects with different glucose tolerance and their relation. Methods: A total of 105 subjects were recruited in this study.Among these subjects,40 were healthy controls with normal glucose tolerance（NGT）,35 had impaired glucose tolerance（IGT）,30 had newly diagnosed type 2 diabetes mellitus（DM）.Plasma Hcy levels were measured by polarization immunoassay（FPIA）,serum CRP concentrations were determined by enzymatic linked immunosorbbent assay（ELISA）,plasma folic acid and vitamin B₁₂ levels were measured by radioimmunoassay. Results: Plasma Hcy concentrations were significantly higher in patients with IGT and DM than in patients with NGT median（25% and 75%）,IGT 7.08（6.45-8.58） μmol/L,DM 8.58（6.97-9.46） μmol/L,NGT 5.64（5.17-8.00） μmol/L,P＜0.05).The serum CRP level median（25%,75%） was 0.37（0.18-0.89）mg/L in patients with NGT and 1.34（0.53-2.79） mg/L in patients with IGT,1.66（1.08-2.27）mg/L in patients with type 2 DM（P＜0.05） respectively,while folic acid and vitamin B₁₂ levels decreased gradually with the worsening glucose tolerance（P＜0.05）.Plasma Hcy concentrations were positively correlated with serum CRP and urine Alb/Cr levels(（r=0.231,P=0.034;r=0.327,P=0.001,respectively）,and negatively correlated with plasma folic acid and vitamin B₁₂ levels（r=-0.294,P=0.003;r=-0.328,P=0.001）. Conclusion: With the worsening of glucose tolerance,the Hcy and CRP levels increase gradually.Deficiency in folic acid and vitamin B₁₂ and insulin resistance might be responsible for the increased Hcy and CRP levels in patients with abnormal glucose tolerance.Hcy and CRP might partially account for the increased risk of developing vasculopathy in patients with abnormal glucose tolerance.