The TiO2 films are deposited on glasses by pulsed laser deposition (PLD), and the effects of substrate temperature and oxygen pressure on the surface morphology, structure and optical properties of TiO2 films are studied. The results show that the refractive index of TiO2 films increases until the substrate temperature reaches 300 ℃, decreases from 300 ℃ to 400 ℃, increases from 400 ℃ to 500 ℃, and gets the maximum at 300 ℃. The refractive index decreases when the oxygen pressure getting higher. The X-ray diffraction (XRD) diagrams demonstrate that the structure of TiO2 films are all amorphous when the growth temperature is under 300 ℃，transforms into anatase structure at 300 ℃, and keeps anatase from 300 ℃ to 500 ℃. The crystallization degree is the best at 300 ℃. The atomic force micrographs (AFM) of the TiO2 films manifest that the particle size increases with the substrate temperature increasing till 300 ℃. When the substrate temperature exceeds 300 ℃, the average particle size remain unchanged almost, and the grain arrangement is best-orderly when the substrate temperature is 300 ℃. According to the transmission spectra, the band gap width of TiO2 thin films is calculated. It is recorgnized that the width of the band gap gets wider while the substrate temperature goes up, but narrower while the oxygen pressure increases.