The purpose of this study is to investigate the effects of medical herb extracts on osteogenesis in MC3T3-E1 cells. Three different medical herbs were extracted using distilled hot water. Extracts’ doses were confirmed using MTT assay and the extracts were applied in differentiation medium every two days. ALP staining and mRNA level tests were performed at day 5 osteogenesis. The mineralization of osteoblast cells was evaluated by using the Alizarin Red S staining at day 14 osteogenesis. Extracts of Phlomis umbrosa (P. umbrosa) and Acanthopanax sessiliflorus (A. sessiliflorus) increased osteogenic differentiation as well as the mRNA level of the osteoblast related genes in MC3T3-E1 cells and the effect was comparable to that of Safflower. These results suggested that extracts of P. umbrosa and A. sessiliflorus may be new therapeutic targets for bone formation.