Titanium dioxide (TiO2) is a wide band gap metal oxide semiconductor with numerous applications in science and technology [1]. The main fields are photovoltaic and photo catalytic for water purification. TiO2 is known to form many polymorph phases, but the most studied TiO2 polymorph phases are anatase, rutile and brookite. It is known that the anatase is more favorable for photo catalytic applications, while the rutile exhibits better optical and electrical performance [2]. In recent years, researchers started to focus on anatase/rutile heterostructures, which showed improved photo catalytic efficiency. In this study, the effects of laser radiation on TiO2 crystal were investigated with aim to show the possibility of phase transition from rutile to anatase. Nb:0.05wt% doped TiO2 crystal was used in experiments. The crystal was irradiated by fourth harmonic of Nd:YAG laser with following parameters: λ=266 nm, τ=3 ns, intensity I=56.0 MW/cm2. The sample was irradiated in one spot from 1 till 10000 laser pulses. From Raman scattering spectra, it can be seen that the crystal consists of rutile phase before the irradiation. However, after irradiation the crystal is transformed in to the anatase phase, as can be seen in Raman scattering spectra [3]. References [1] M. Grätzel, Nature 414, 338 (2001). [2] H. Cheng and A. Selloni, Phys. Rev. B 79, 092101 (2009). [3] H.L.Ma, J.Y.Yang et al. Appl.Surf. Sc. 253, 7497(2007)