HAp and Zr-doped HAp nanoparticles were synthesized from bovine bone and local zircon material by using the hydrothermal method. XRD analysis showed that the HAp and Zr-doped HAp nanoparticles had hexagonal structure with a crystallite size of 20-36 nm and the lattice constants a = 9.8-9.9? and c = 6.5-6.8 ?. XRD data also showed that up to 20 at.% of Zr can be accommodated in HAp crystal structure. The lattice constant and cell volume decreased with increasing Zr concentration. FTIR data confirmed that the majority of functional groups that exist on the surface of the HAp and Zr-doped HAp nanoparticles were the hydroxyl and phosphate groups. Suspensions with the HAp and Zr-doped HAp nanoparticles prepared using citric acid as dispersant were stable with zeta potential between ?31 and ?35mV at pH = 7. Reactive oxygen species are generated on the produced HAp and Zr-doped Hap nanoparticles and confirm their potential for application in photodynamic therapy.