In this paper, we fabricate a freestanding plasmonic cascade grating and investigate the extraordinary optical behaviors associated with it. The structure consists of two identical metallic gratings with nearly perfect alignment on the lateral direction supported by a Si3N4 membrane. Two types of optical transmission resonances emerge in the fabricated sample at visible frequencies, corresponding to the electric and magnetic resonances in the cascaded structure. These resonances respectively originate from the near-field coupling of plasmonic symmetric and antisymmetric modes in the metal-dielectric-metal waveguide. Moreover, the influence of the incident angle and structure parameters on two resonant peaks are investigated. We envision that this type of plasmonic free-standing cascaded nanostructure holds promise for a series of spectrum-dependent applications for the visible light.