OBJECTIVE: To study the effect of astragaloside IV on the expression of cytokines in bone mesenchymal stem cells (MSCs) in rats. METHODS: MSCs were isolated from Wistar rats by the method of adhesive cultiration and clone, and then their biological activities were assessed using indirect immunofluorescence. Proliferation of MSCs stimulated with astragaloside IV was ascertained by the MTT method. Expression of cytokines was ascertained using RT-PCR in MSCs with astragaloside IV stimulation or not. RESULTS: MSCs were effectively isolated and purified in vitro, and had expression of many cytokines except IL-3, such as stem cell factor (SCF), thrombopoietin (TPO), granulocyte macrophage colony stimulating factor (GM-CSF) and transforming growth factor (TGF-β1). Astragaloside IV stimulation promoted MSCs proliferation, and 200 mg/mL astragaloside IV treatment produced a peak effect 72 hrs after culture. The SCF expression in MSCs stimulated with astragaloside IV increased significantly compared with that in MSCs without astragaloside IV stimulation. CONCLUSIONS: Astragaloside IV may promote MSCs proliferation and increase SCF secretion in vitro.［Chin J Contemp Pediatr, 2010, 12 (4):290-292］