This study aimed at the proliferation and differentiation of osteoblastic cells on silicon-doped TiO₂ and pure TiO₂ films prepared by cathodic arc deposition. The films were examined by X-ray photo-electron spectroscopy, which showed that silicon was successfully doped into the Si-TiO₂ film. Meanwhile, no significant difference was found between the surface morphology of silicon-doped TiO₂ and pure TiO₂ films. When osteoblastic cells were cultured on silicon-doped TiO₂ film, accelerated cell proliferation was observed. Furthermore, cell differentiation was evaluated using alkaline phosphatase (ALP), type I collagen (COL I) and osteocalcin (OC) as differentiation markers. It was found that ALP activity, the expression levels of OC gene, COL I gene and protein were up-regulated on silicon-doped TiO₂ film at 3 and 5 days of culture. Moreover, no significant difference was found in apoptosis between the cells cultured on silicon-doped TiO₂ and pure TiO₂ films. Therefore, findings from this study indicate that silicon-doped film favors osteoblastic proliferation and differentiation, and has the potential for surface modification of implants in the future.