Abstract: [SiO 2 /FePt] 5 /Ag thin films were deposited by RF magnetron sputtering on the glass substrates and post annealing at 550 ℃ for 30 min in vacuum. Vibrating sample magnetometer and X-ray diffraction analyser were applied to study the magnetic properties and microstructures of the films. The results show that without Ag underlayer [SiO 2 /FePt] 5 films deposited onto the glass are FCC disordered; with the addition of Ag underlayer [SiO 2 /FePt] 5 /Ag films are changed into L1 0 and (111) mixed texture. The variation of the SiO 2 nonmagnetic layer thickness in [SiO 2 /FePt] 5 /Ag films indicates that SiO 2 -doping plays an important role in improving the order parameter and the perpendicular magnetic anisotropy, and reducing the grain size and intergrain interactions. By controlling SiO 2 thickness the highly perpendicular magnetic anisotropy can be obtained in the [SiO 2 (0.6 nm)/FePt (3 nm)] 5 /Ag (50 nm) films and highly (001)-oriented films can be obtained in the [SiO 2 (2 nm)/FePt (3 nm)] 5 /Ag (50 nm) films.