Demineralized bone particles(DBP) exhibit osteoinductive properties and are very useful for bone formation and other orthopeadic applications. In this study, we investigated the osteogenic capabilities of rat bone marrow stromal cells(rBMSCs) in PLGA scaffold impregnated with various DBP contents. DBP-loaded PLGA scaffold (10, 20, 40, 80 % w/w) were prepared by solvent casting/salt leaching method. rBMSCs were seeded in PLGA and DBP/PLGA scaffolds, and then cellular viability and proliferation were assayed by water-soluble tetrazolium salt(WST-8) assay. Osteoblast differentiation of cells were analyzed by alkaline phosphatase(ALP) activity. Finally, reverse transcript polymerase chain reaction(RT-PCR) was assessed to measure mRNA expression of the genes (ALP, osteocalcine and type I collagen) of osteogenic marker in rBMSCs depending on various content of DBP. These results could demonstrated that presence of DBP in PLGA might play important roles in osteoblast differentiation of rBMSCs.