Introduction: The endothelium plays an important role in maintaining vascular structure and waits; and endothelial cells are protective against the thrombosis and atherosclerosis. Cardiovascular risk factors, such as metabolic diseases, systemic and local inflammations, result in endothelial dysfunction. Nitric oxide is one of the endothelium derived substances that has an important role in maintaining the endothelial homeostasis. The asymmetric dimethylarginine (ADMA) is the endogenous inhibitor of the nitric oxide synthase. ADMA has been shown to impair the endothelial function and to be associated with hypercholesterolemia, hyperhomocysteinemia, and atherosclerosis. Ascorbic acid, a vitamin with reductant and antioxidant effects, can improve endothelial function and decrease the reactive oxygen species level. Our objective was to determine pathologically exogenous ADMA effect on endothelium of abdominal aorta, and to observe protective effect of antioxidant ascorbic acid.