Aim To investigate the relationship between vascular function destroy and microinflammation in the patients with uremia before dialysis. Methods 95 patients were selected randomizedly as test group,and 40 normal individuals as control.Carotid artery intima-media thickness(IMT),cross-sectional calculated intima-media area(IMA),plaques,endothelium-dependent dilation(EDD) and endothelium-independent dilation(EID) of brachial artery were determined with non-invasive high-resolution B-mode ultrasonography.Serum levels of C-reactive protein(CRP) and tumor necrosis factor-α(TNF-α) were also determined. Results Compared with normal control,levels of serum CRP(5.27±1.18 mg/L vs 1.54±0.82 mg/L,P<0.05),TNF-α(2.11±0.34 μg/L vs 0.15±0.03 μg/L,P<0.05)were significantly higher in patients with uremia.Lower levels of serum proalbumin and hemoglobin,and higher systolic and diastolic pressure were found in the patients.However,it has no difference about serum albumin,glucose and lipids between the two groups.There was no difference in IMT,IMA,percentage of plaques,basal inner diameter and blood flow of brachial artery between the two groups.But,endothelium-dependent dilation(EDD),endothelium-independent dilation(EID),blood flow of response hyperemia,blood flow after buccal nitroglycerin of brachial artery were decreased significantly in the patients group.Serum levels of CRP and TNF-α were correlated negatively with EDD and EID(P<0.05). Conclusion These data suggest that the microinflammation plays an important role in the pathogenesis of vascular dysfunction in the pre-dialysis patients with uremia.