Aim To explore the effect of total spaonins of panax notoginseng(tPNS) on the proliferation of vascular smooth muscle cell(VSMC) induced by platelet derived growth factor(PDGF) and the possible underlying mechanisms. Methods Cell proliferating model of rabbit aorta VSMC induced by PDGF-BB was established.The proliferative activity of VSMC with tPNS was analyzed by MTT method; the effect of tPNS on cell cycle of VSMC was observed by flow cytomytry technique;the effect of tPNS on c-myc gene expression in VSMC was observed by immunocytochemical method. Results MTT metabolism of VSMC in the basic and PDGF-BB stimulated situation was inhibited by tPNS,and the cells numbers of G_0/G_1 phase were increased and that of G_2/S phase were decreased markedly.At the same time,highly expression of c-myc gene protein stimulated by PDGF could be inhibited by tPNS significantly. Conclusions tPNS can inhibit the proliferation of VSMC induced by PDGF significantly,at least in part by preventing VSMC from G_0/G_1 phase entering S phase and downgulating the expression of oncogene c-myc protein.