The phase transformation of rutile TiO2 single crystal irradiated by femtosecond laser pulses was studied by micro-Raman spectroscopy. It is found that when the femtosecond laser average power is 300 mW, with the increase of irradiation time, the intensity of Raman active mode Eg increases while that of A1g decreases, which suggests that the color center is induced. When the irradiation time is about 10 s, the component of anatase emerges and with increase of the irradiation time the intensity of Raman active modes of anatase increases while that of rutile decreases. But if the irradiation time is 1/63 s, with the increase of average power of laser, the intensity of Eg increases and that of A1g decreases apparently within the ablation crater, and no anatase appears.