The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on ${eta}-tricalcium$ phosphate (${eta}-TCP$) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM ${eta}$-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor ${kappa}B$ ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-Ⅰ (COL-Ⅰ). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on ${eta}-TCP(+/-)$. According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/${eta}-TCP(-)$ than DOCs/${eta}-TCP(+)$. According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/${eta}-TCP(+)$ compared to that of DOCs/${eta}-TCP(-)$ on rhBMP 10 ng/ml. Our study presented the ${eta}-TCP$ will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.