Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase (NOS), which inhibits the formation of vasoactive substance, nitric oxide (NO), and further results in endothelial dysfunction. It is considered as a new predictor for endothelial dysfunction. Some researches have shown that ADMA is a risk factor of atherosclerosis, hypertension and ischemic stroke. In recent years, studies also showed that ADMA may cause cerebral blood flow autoregulation dysfunction, chronic low perfusion and blood-brain barrier damage, and is involved in the incidence and development of leukoaraiosis. Interference of the synthesis or metabolism of ADMA may bring forward a new means for the prevention and treatment of vasculopathy.