FeCoZr magnetic thin films with high uni-axial anisotropy were fabricated by RF co-sputtering followed by post magnetic annealing. The crystal size of FeCoZr films was less than 15 nm, as calculated by Scherrer equation from X-ray diffraction patterns. By adding Zr element, FeCoZr films exhibited a uni-axial anisotropy after magnetic field annealing at 400 °C for 1 hr. Optimal high frequency ferromagnetic properties were achieved in film with 19 at.% Zr, in which strong uni-axial anisotropy field of 300 Oe and high ferromagnetic resonance frequency in excess of 5.2 GHz were obtained. These facts suggest that FeCoZr nano-crystalline film is a potential candidate in high frequency electromagnetic devices operating at GHz bands.