The migration of vascular smooth muscle cells (VSMCs) is the main step in neointimal formation in restenosis and athersclerosis.Tropomodulin1 (Tmod1) is a capping protein of actin filament and expressed in VSMCs.This study is to investigate the role of Tmod1 in VSMC migration.Rat VSMCs were treated with PDGF and quantitative PCR (qPCR) showed that Tmodl is upregtulated.In balloon-injured rat carotid artery, Tmod1 expression was enhanced in the neointima as shown by qPCR, Western blot and immunohistochemistry.Tmod1 level was knocked down by small interfering RNA (siRNA) and VSMC migration was assessed by wound healing assay.Data showed that Tmodl knockdown significantly inhibited the migration of VSMCs.Tmod1-EGFP fusion protein was expressed in VSMCs and confocal images showed the localization of Tmodl in the stress fibres.Confocal microscopy also showed the disruption of stress fibres in the VSMCs with Tmdol knockdown.Data suggests that Tmodl is involved in the VSMC migration and neointimal formation.