The accumulation of asymmetric dimethylarginine （ADMA）has been demonstrated to be correlated with the development and progression of diabetic vascular complications including cardiovascular or cerebrovascular disease,nephropathy and retinopathy. ADMA can inhibit nitric oxide synthase （NOS） activity and reduce nitric oxide （NO） synthesis,thereafter to promote endothelial dysfunction and mediate the occurrence and development of diabetic vascular diseases.