Sc:Ce:LiTaO crystals were grown by using the Czochralski method. The two-wave coupling experiments and transmitted facula distortion method were used to measuring the photorefractive properties and the optical damage resistance, respectively. It was found that the photorefractive response speed of Sc:Ce:LiTaO was four times faster than that of Ce:LiTaO and the resistance ability to optical damage was two orders higher than that of Ce:LiTaO. It could be attributed to the Ce ions losing their electron acceptor properties, which result in the increase of photoconductivity. In this paper, site occupation mechanism of impurities was also discussed to explain the increased of photoconductivity.