Abstract:Previous studies have shown that proliferation and migration of vascular smooth muscle cells (VSMCs) are the common pathological basis of the development and progression of atherosclerosis， hypertension and vascular restenosis after surgical interventions. It is also known that， in the proliferation and migration process， VSMCs phenotypic switching plays an important role. Myocardin， the most critical transcription co-factor specifically expressed in adult cardiomyocytes and smooth muscle cells (SMCs)， can effectively promotes the differentiation of SMCs. Recently， a number of studies have unveiled the functions of myocardin in SMCs phenotypic switching. In this review， recent findings on VSMCs phenotypic switching and the roles of myocardin in this process will be summarized and discussed.