Co-doped TiO2 ferromagnetic semiconductor flms were prepared by rf co-sputteri ng method and then annealed in vacuum at 300℃ for 2 h. Superconducting quantum interference device (SQUID) measurements indicate that the samples are ferromagn etic and the Curie temperature is above 300K. The saturation magnetization, coer civity, and saturation field are 55emu/cm3, 400×80A/m and 1500×80A/m at room temperature, respectively. And the magnetic moment was observed to be 0679 μB/Co. No pure Co metal grains were found by x-ray diffraction and x-ray p hotoemission spectroscopy measurements.