Aim To investigate the effects of simvastation on the proliferation and migration of rat adventitial fibroblasts as well as collagen synthesis. Metheods Isolated vascular adventitial fibroblast (VAF) of Sprague-Dawley(SD) rats were cultured. VAF proliferation was measured by thiazolyl (MTT) blue assay. The migration of VAF was determined by Sarkar's technique. Collagen synthesis was measured by 3H-proline uptake test. Results (1)MTT colorimetry showed the A490 values were 0.291±0.011, 0.265±0.006, 0.234±0.008 and 0.214±0.006 respectively in the 10 -7 mol/L, 10 -6 mol/L, 10 -5 mol/L and 10 -4 mol/L simvatastin groups, all significantly lower than that in the control group (0.335±0.082, all p<0.01). (2)The distance of migration was 6.5±1.1 mm, 5.3±1.2 mm, 4.1±1.0 mm and 2.9±0.9 mm respectively in the 10 -7 mol/L, 10 -6 mol/L, 10 -5 mol/L and 10 -4 mol/L simvastatin groups, all significantly lower than that in the control group (8.1±1.8, all p<0.01). (3)The 3H proline uptake was (c/min)385±51, 272±48, 161±38 and 141±36 respectively in the 10 -7 mol/L, 10 -6 mol/L, 10 -5 mol/L and 10 -4 mol/L simvastatin groups, all significantly lower than that in the control group (655±58, all p<0.01). Conclusions Simvastatin can effectively inhibit the proliferation,migration and collagen synthesis of rat vascular adventitial fibroblasts in a dose-dependent manner which may play a role in ameliorating vascular remodeling.