The (γ'-Fe4N/Si-N)n (n: number of layers) multilayer films and g0-Fe4N single layer film synthesized on Si (100) substrates by direct current magnetron sputtering were annealed at different xemperatures. The structures and magnetic properties of as-deposited films and films annealed at different temperatures were characterized using X-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The results showed that the insertion of Si-N layer had a significant influence on the structures and magnetic properties of γ'-Fe4N film.Without the addition of Si-N lamination, the iron nitride γ'-Fe4N tended to transform to a-Fe when annealed at the temperatures over 300℃. However, the phase transition from γ'-Fe4N to e-Fe3N occurred at annealing temperature of 300℃ for the multilayer films. Furthermore, with increasing annealing temperature up to 400℃or above, e-Fe3N transformed back into γ'-Fe4N. The magnetic investigations indicated that coercivity of magnetic phase γ'-Fe4N for as-deposited films decreased from 152 Oe (for single layer) to 57.23 Oe with increasing n up to 30. For the annealed multilayer films, the coercivity values decreased with increasing annealing temperature, except that the film annealed at 300℃ due to the appearance of phase e-Fe3N.