Bone morphogenetic proteins (BMPs) are members of the TGF-beta superfamily of growth factors. Microarray technology for gene expression profiling has evolved rapidly and provides a powerful tool in studying differentiation. To investigate the osteoblastic differentiation gene expressions that contribute to BMP-2 dependent osteogenesis, we performed gene expression profiling on BMP-2-treated mouse bone marrow stromal cells. Specifically, D1 cells (mouse bone marrow stromal cells) were cultured in osteogenic differentiation medium (ODM) for 3 days, and next treated with BMP- 2 for 24 h. Total RNA was extracted using Trizol buffer and purified using RNeasy columns. Total RNA was amplified and purified using the Ambion Illumina RNA amplification kit to yield biotinylated cRNA. And, we confirmed up- and down-regulation genes by RT-PCR. We analyzed up- and down-regulation of genes by 1.5-fold expression, divided genes into two categories: biological process and molecular function. Two categories consisted of 49 groups containing 25,697 genes. We detected 42 mRNAs that were differentially up-regulated after BMP-2 stimulation and 20 mRNAs that were differentially down-regulated. And, we confirmed up-regulation 8 genes expression and down-regulation 4 genes expression by RT-PCR. These data indicate that BMP-2 regulate various genes expression during osteoblastic differentiation.