Pulsed laser deposition is used to prepare hydroxyapatite (HA) thin films onto Ti6Al4V (TC4) substrate, and the influence of the annealing temperature on the microstructure and properties is investigated. The morphology, composition and microstructure of the HA films are detected by the scanning electron microscope (SEM), the energy disperse spectroscopy (EDS), X-ray diffraction and the Fourier transform infrared (FTIR) spectroscopy, respectively. The surface roughness and wettability are investigated separately by the profilometer and the contact angle measurement. The experimental results demonstrat that the as-deposited film is compact and defect-free, which is mainly composed of amorphous phase. After heat treatment, the film has a higher crystallinity and roughness, and the ratio of Ca/P is closer to that of HA, and the surface becomes more hydrophilia compared with the bare substrate and the as-deposited one. However, the exorbitant annealing temperature (700 ℃) can result in microcracks on the film.