Since bacterial accumulation surrounding biomaterials has pathogens known to cause the biomaterials centered infection, it may be important to develop some kind of biomaterial with antibacterial activity as well as biocompatibility. This study focused on evaluating the antibacterial activity of silver-hydroxyapatite/ Titania nanoparticles (Ag-nHA/nTiO2) against oral bacteria with agar dilution method. Bacteria were seeded on agar plate containing antibacterial material with different concentrations after incubation of 48 hours. The antibacterial activity was demonstrated by MICs. The MICs of Ag-nHA/nTiO2 ranged between 1000μg/ ml and 7500μg /ml under anaerobic conditions. And it also exhibited remarkable antibacterial activity to all the aerobe bacteria (MIC≤500μg/ml). On the other hand, the antibacterial activities of Ag-nHA/nTiO2 differentiate to some extent with the bacterial strains. This Ag-nHA/nTiO2 exhibited remarkable antibacterial activity to anaerobic and aerobe bacteria. This antibacterial effect may reduce the potential for bacterial colonisation of oral biomaterials with Ag-nHA/nTiO2.