Arteriosclerosis occlusive (ASO) is a manifestation of atherosclerosis (AS), and it is one of the main causes of lower limb ischemic necrosis in the elderly. Excessive proliferation and migration of vascular smooth muscle cells is one of the main causes of ASO, but the mechanism is unclear. MiR-125b is a tumor suppressor, which can inhibit the proliferation and migration in various kinds of tumors. At the same time, we find miR-125b is the most obviously down-regulated microRNA in ASO. Therefore, we explore the role of miR-125b in ASO. This study shows that up-regulated miR-125b inhibits the proliferation of vascular smooth muscle cells through CCK8 assay and Brdu assay. Meantime, the up-regulation of miR-125b restricts the migration of vascular smooth muscle cells through trans-well assay and wound healing assay. Furthermore, this study finds that up-regulated miR-125b inhibits the expression level of angio-associated migratory cell protein (AAMP) and serum response factor (SRF), which may be an important way for miR-125b to regulate the proliferation and metastasis of smooth muscle cells.