Abstract: Vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs) are closely connected and affect each other functionally. VECs can regulate the phenotypic transition of VSMCs directly (Notch signaling pathway) or indirectly (cytokines, exosomes) in respond to external stimuli such as hypoxia, inflammation or abnormal mechanical forces and maintain vascular homeostasis. The abnormal process is an important cause of arterial vascular diseases such as atherosclerosis, aortic aneurysm and aortic dissection. In this paper, the mechanism of VECs regulating phenotypic transformation of VSMCs is reviewed.