Intrinsic TiO_2films were prepared by RF-magnetron sputtering at diff erent working pressures (0.2Pa－4.0Pa).All as-deposited intrinsic TiO_2film s show hysteresis behavior from 2K to 340K,and the largest room temperature (RT) saturation magnetization (M_s) is 1.96emu/cm^3for the amorphous TiO_2film deposited at 2.0Pa. From the X-ray diffraction (XRD) patterns of TiO_2films,we observe that the rutile and anatase crystal structures coexist in the TiO_2films at 0.2Pa.With the working pressure increasing,the transformation b etween the rutile crystalline and anatase crystalline appears.When the working pressure is increased to 2.0Pa, the crystalline state of TiO_2film changes from polycrystalline to amorphous.Using the high resolution transmissio n electron microscopy (HRTEM),we can observe the crystalline t ransformation by the electron diffraction pattern and HRTEM image clearly.The tr ansmission spectra of TiO_2films are measured by the spectrophotometer,the visible (VIS) transmittance of TiO_2films is more than 85%,the absorption edge shifts to the longer wavelength with the amorphous transformation,and the E_g decreases to 3.14eV,so the increasing structural defects play an important role in the ferromagnetism of intrinsic TiO_2films.I n addition,all of as-deposited samples are high-resistance state and the resistivity is higher than 10⁷Ω·cm.We can rule out the effect of the carrier-mediated RKKY coupling on the system ferromagnetism.