Single layer HfO2 thin films have been prepared respectively by Electron Beam Evaporation (EBD), Ion Assisted Deposition (IAD) and Ion Beam Reactive Sputtering (IBRS). Crystal structures, optical properties, surface topography and absorption of these deposited films have been studied. It is found that thin film properties have a close relationship with deposition technologies. The EBD and IBRS films are largely amorphous, whereas the IAD films are polycrystalline. Comparison with EBD films, the IAD and IBRS films, of which the structures are very compact, display higher refractive index, surface roughness and absorption. The optical band gap energy of these films are found to be 5.30～5.43 eV, and the corresponding optical absorption edge range are found to be from 228.4 nm to 234.0 nm.