Aim To study the Changes of serum soluble intercellular adhesion molecule-1(sICAM-1) and its relations with endothelial dysfunction in type 2 diabetes mellitus patients. Methods 62 cases of type 2 diabetes were divided into three groups: complication free group(n=19),microangiopathy group(n=20) and macroangiopathy group(n=23).20 normal subjects were served as normal control group(n=20).Levels of sICAM-1 and von Willebrand factor(vWF) were measured by enzyme linked immunosorbent assay(ELISA). Results The levels of sICAM-1 and vWF in type 2 diabetes mellitus were higher than those in healthy controls(p<(0.01)).The levels of sICAM-1 and vWF in type 2 diabetic patients with microangiopathy were higher than those without vascular complication(p<(0.01)),but lower than those with macroangiopathy(p<(0.01)).The levels of vWF in type 2 diabetic patients without vascular complication were not higher than those in healthy controls (p<0.05).There was a significant positive correlation between sICAM-1 and vWF,triglyceride and diastolic blood pressure(r=0.43,r=0.45, r=0.52 and r=0.62,p<0.01). Conclusions Serum sICAM-1 might participate in the course of diabetic microangiopathy.The measurement of serum sICAM-1 levels in type 2 diabetes mellitus may be clinically useful for early discovering of endothelial dysfunction.