Abstract: Objective To explore the clinical significance of changes in urine microalbumin (UM) and endothelin (ET) in different courses of type 2 diabetes. Methods A clinical analyses of 30 type 2 diabetic patients with vascular complications (group A) was conducted in comparison with type 2 diabetic patients without vascular complications (group B) and patients with impaired glucose tolerance (IGT, group C). With 30 healthy subjects with family history of type 2 diabetes (group D) and 30 healthy subjects without such family history (group E) as controls, UM and ET were determined in all the subjects for a statistical analysis. Results Significant differences in UM content was noted between group A and the other 4 groups (P<0.05), while the content did not differ significantly between the latter 4 groups (P>0.05). ET content was significantly higher in group A than in the other 4 groups (P<0.01), and was the lowest in group E (P<0.01). Conclusions Type 2 diabetic patients sustain extensively impaired endothelium function, which is exacerbatesd with the progression of the disease courses. Synchronized changes between vascular complications and impaired endothelium function indicates that vascular endothelial injury relates to vascular complications and the progression of diabetes.