Background & Object : The differentiation of osteoblasts controlled by various growth factors and matrix proteins expression in bone. The aim of this study was to identify the Astragalus membranaceus that may induce the osteogenic activity in human osteoblast-like SaOS-2 cells. Methods : The osteogenic activity of Astragalus membranaceus were evaluated by WST-8 assay, ALP activity, RT-PCR analysis of VEGF, OCN, OPN, Col I mRNA, and ELISA or colorimetric analysis, and mineralization by Alizarin red staining in SaOS-2 cells. Results : Astragalus membranaceus had no effect on viability of osteoblastic cells, and dose dependently increased alkaline phosphatase (ALP) activity. Astragalus membranaceus markedly increased mRNA expression for vascular endothelial growth factor (VEGF), osteocalcin (OCN), osteopontin (OPN), and type I collagen (Col 1) in SaOS-2 cells. Extracellular accumulation of proteins such as VEGF, and Col I was increased in a dose-dependent manner. Also, Astragalus membranaceus significantly induced mineralization in the culture of SaOS-2 cells. Conclusion : This study showed that Astragalus membranaceus not affect on viability, but it enhanced ALP activity, VEGF, bone matrix proteins such as OCN, OPN and Col I, and mineralization in SaOS-2 cells. These results propose that Astragalus membranaceus plays an important role in osteoblastic bone formation, and possibly lead to the development of bone-forming drug.