We have studied the effective refraction index of the guided wave mode in periodic layered ferrite-dielectric/metal film composites. Using the equivalent transmission line approach we have analyzed and calculated the dispersion characters and then the effective refraction index of the composites. We have found that the effective refraction index of the composites will be negative within a certain frequencies only when the wave is in TE mode. The loss of the composite is closely related to the dielectric layers, which can be effectively reduced by decrease the dielectric loss. However, too small dielectric loss results in disappearing of the negative refraction index.