Hydroxyapatite (HAP) nanoparticles were synthesized by sol-gel method at 75°C. In this low temperature synthesized HAP nano particles were involved various biomedical applications like bone defects, bone augmentation, as well as implant coating. For this synthesized HAP were examined functional groups, microstructure and phase analysis by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD spectrum of dried HAP precursor confirms that crystallite size below 45 nm and FTIR spectrum conforms the functional groups of phosphate (PO4 3-) and hydroxyl (O-H) groups, SEM images of HAP appears in a platelets shape, this platelets size in (30-75) nm.