In this study, we investigated pharmacologic activity of rice bran ethyl acetate fraction (RBE), based on their osteoblast enhancing effects. It has been found that REB have a stimulatory effect on the commitment of bi-potential mesenchymal precursor C2C12 cells into osteoblasts in the presence of BMP-2. Furthermore, RBE enhanced the BMP-2-stimulated induction of ALP, an early phase biomarker of osteoblast differentiation. In addition, Western blot analysis showed RBE enhanced the BMP-2-stimulated phosphorylation of p38, but not those of ERK or JNK. These findings show RBE has the potential to enhance the BMP-2-mediated commitment of C2C12 cells into osteoblasts and their differentiation through p38 activation.