A novel diblock copolymer composed of bisphosphonate and pyridine oligomers has been prepared by reversible additionfragmentation transfer (RAFT) polymerization. Ag ion was introduced into the polymer via its coordination with the pyridine groups, followed by a reduction process to obtain Ag nanoparticles with diameters of 515 nm measured by transmission electron microscopy (TEM). In addition, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) proved successful introduction of Ag nanoparticles into polymer. Ag nanoparticles containing polymer exhibited excellent antibacterial properties toward Lactobacillus plantarum (L. plantarum). In order to investigate its practical application as an antibacterial coating, the synthesized polymer was tethered onto hydroxyapatite (HA, main mineral component of natural bone, teeth, and most of implants for bone repair) surfaces via interaction between the polymers bisphosphonate group and HA, forming similar to 4 nm thick layers. Ag nanoparticles (515 nm in diameter) uniformly distributed around the HA particles were fabricated following the above process. The ability of the coating to kill the bacteria L. plantarum was determined, which revealed strong antibacterial properties.