Abstract: Objective: To explore the changes of carotid intima-media thickness(IMT) and vascular endothelium function in people with impaired fasting glucose(IFG) as well as the risk factors. Methods: The anthropometric variables,fasting blood glucose(FBG),2-hour postprandial blood glucose (PBG), fasting blood insulin (FINS), postprandial blood insulin (PINS), systolic pressure (SBP), diastolic pressure(DBP),blood lipid and other clinical parameters were measured in 30 controls with normal glucose tolerance(NGT) and 45 people with impaired fasting glucose(IFG). The carotid IMT was measured by color Doppler ultrasound,the blood endothelin 1 (ET-1) was tested by enzyme-linked immune sorbent assay (ELISA) and the blood nitric oxide(NO) by nitrate reductase assay in all the subjects. Results: There were significant differences in the levels of IMT,ET-1 and NO between IFG group and NGT group(P < 0.01). According to linear correlation analysis, IMT showed positive correlation with body mass index (BMI), SBP, blood NO, triglyceride(TG),ET-1,FINS,HOMA insulin resistance index (HOMA-IR) and DBP respectively(P < 0.05-P < 0.01); the level of blood NO showed positive correlation with IMT,SBP,ET-1,TG,FINS,HOMA-IR,HOMA-β cell function index(HOMA-β) and DBP, respectively(P < 0.05-P < 0.01). The level of blood ET-1 showed positive correlation with IMT,SBP,NO,BMI,FINS,HOMA-IR, HOMA-β and TG,respectively(P < 0.05-P < 0.01). According to multiple regression analysis,the risk factors of IMT were NO,TG, FBG and ET-1 in sequence,the risk factors of blood ET-1 were blood NO and PBG,and the risk factors of blood NO were SBP and ET-1 in sequence. Conclusions: The IMT,blood ET-1 and NO increase greatly in adults with impaired fasting glucose,and their vascular endothelial function has changed significantly compared with that of people with NGT. Early intervention may improve the islet function of IFG population and thus reduces the genesis of diabetes and atherosclerosis.