Abstract: The transmission properties and magnetotunability of a magnetoinductive device with bilayered ferrite structure were investigated, and the effect of structural parameters on the properties of microwave was discussed. When two magnetized ferrite slabs are parallelly placed, the coupling of the resonanting modes of surface wave results in magnetoinductive wave, which propagates across the composite structure. In the transmission spectra, a passband appears in the frequency range of the forbidden band which is produced by ferromagnetic resonance. The center frequency of the passband shifts to a higher frequency when the bias magnetic field increases. That is good magnetotunability. With the increase of the distance between the two ferrite slabs, the coupling between surface waves fades gradually, the half-width decreases, and the transmission loss increases.