TiO2 thin films of about 200 nm thickness were prepared by RF magnetron sputtering on quartz substrates at room temperature,and then annealed by a KrF pulse laser with wavelength 248 nm under different power densities in the air. The effect of laser power density on the characteristics of films was systematically analyzed using X-ray diffractometry(XRD),Raman spectra,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),atom force microscopy(AFM),high resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED) and UV-vis spectrophotometer. The results showed that high-quality anatase TiO2 films can be obtained when the power density was 0.5 J/cm2. By increasing the power density continually,TiO2 showed the predominant orientation with rutile phase along(1 1 0) reflection,with roughness of the films increasing.