Hydroxyapatite bone granules with a macroporous structure were produced and then adsorbed with basic fibroblast growth factor (FGF2). The in vitro scaffolding role of the granules in cell population and osteogenic differentiation was investigated. The FGF2-adsorbed porous granules allowed the MC3T3-E1 cells to adhere well and then proliferate actively. While the cell growth level on the FGF2-treated granules was observed to be similar to that on the untreated granules, the expression of genes associated with bone, including collagen type I, alkaline phosphatase, and osteocalcin was significantly upregulated by the FGF2 treatment, particularly at the early stage. Moreover, the production of alkaline phosphatase with prolonged culturing was greatly enhanced on the FGF2-adsorbed granules. Taken together, the FGF2 treatment of the hydroxyapatite granules was effective in the osteogenic development and the FGF2-adsorbed bone granules may be useful in bone regeneration area.