Abstract: Nitric oxide (NO),well known as the endothelium-derived relaxing factor (EDRF),has become increasingly recognized as an important determinant of cardiovascular diseases.A molecular pathway by which NO accomplishes various biochemical processes is the cGMP-independent post-translational modification of protein,S-nitrosylation.Here we review the biochemistry and regulating mechanisms of NO-related S-nitrosylation of proteins,and discuss the multiple roles of S-nitrosylation in vascular functions and pathology in particular.