Aim To explore the effect of coixan on endothelium-1 (ET-1) gene expression of type 2 diabetic model on rat arota. Methods The experimental type 2 diabetic rats were yielded by i.p streptozotocin (75 mg/kg) and feeding hyperotrophic foods,then to observe ET-1 gene expression by RT-PCR. Results After 6 months of i.p streptozotocin, the ET-1 gene expression 0.72±0.10 on rat arotic enhanced obviously, the comparison between normal group 0.39±0.01 (p<0.01), ET-1 mRNA gene expression of administered groups downregulate (p<0.05), and the ET-1 gene expression of coixan i.p group 0.49±0.12 showed more significant difference than the model control group (p<0.01). Conclusion Diabetic vascular complication may be related to upregulation of ET-1 mRNA gene expression,Coixan decreased ET-1 mRNA gene expression.