A magneto-photonic crystal (MPC) is defined as a periodic light-guided structure involving magnetic materials or a photonic crystal with some magnetic-material defects. The transfer matrices of guided optical waves (GOWs) propagating respectively in magneto-optical and non-magnetic dielectric layers are deduced according to the coupled-mode theory. The transmission spectra of GOWs in one-dimensional magneto-photonic crystals (1D-MPC) are investigated by the transfer matrix method. It is shown that the two sharp peaks in the 1D-MPC’s transmission spectra can be used for high-resolution magnetic field sensing; and a comb filter with six channels can be achieved by optimizing the 1D-MPC structure and controlling the external magnetic field. This work has been supported by the National Natural Science Foundation of China (Grant No:60671027)