Beta-tricalcium phosphate (β-TCP) has been used for bone regeneration with satisfactory clinical results in accelerating bone formation. However, little is known about the molecular mechanisms enhancing the bone formation by β-TCP. To understand this mechanism, β-TCP was implanted into bone defects of the mandible in beagles and gene expression profiles were examined using DNA microarray technology. β-TCP altered many gene expressions ; among those genes, a significantly higher mRNA level of platelet-derived growth factor receptor beta (PDGFRB) was observed. The enhanced PDGFRB gene expression level was successfully confirmed by reverse transcription-polymerase chain reaction and real-time polymerase chain reaction. Immunohistochemical study using antibody against PDGFRB also demonstrated that PDGFRB protein expression was enhanced by β-TCP. Because PDGFRB is a potent regulator of mesenchymal cell function of wound healing and osteogenic differentiation, the enhancement of the PDGFRB gene expression by β-TCP may be an important mechanism in accelerating bone formation.