By means of magnetron sputtering, the Fe-Y coatings containing 15.4%, 20.7% and 32.7% Y (atom fraction), were deposited on stainless steels. The sputtered coatings were investigated by discontinuous weigh measurement. The results indicate that the oxidation kinetics can be divided into three stages, of which the first and second stages obey the parabolic rate law, while the oxidation kinetic curves of the last stage nearly exhibits horizontal lines. With the increase of the content of Y, the oxidation rate obviously increases. The external scale of the three kinds of alloys is substantially similar. After 24-h oxidation at 800 °C under 1 atm of air, the surface of sputtered coating is mainly transformed into three types of oxide scales, of which the thin outermost layer was Fe2O3, the innermost is YFeO3 mixed with double oxides including FeO or Fe3O4. Single Y2O3 layer was not formed on the surface or in the alloys. The results were disscussed by taking into account the defects in the metal oxide, the self-diffusion of the elements in the alloys, and the low diffusion of yttrium in iron.