The field distribution over a split ring resonator is expanded into Floquet modes，revealing the fact that the evanescent floquet modes actually lead to the metamaterial resonance behavior. Transmission through metamaterials is examined for arbitrary incident wave. It is shown that the resonance happens in the transmitted modes with the same polarization as that of the wave incident in the main plane. The electric and the magnetic resonances vary with the incidence angle. For the wave from other incident planes，the TE- and TM- Floquet modes will share the resonance.