Abstract: In this paper, we present a double L-shaped surface plasmonic rectangular-ring resonator waveguide. The dependence of the transmission characteristic of the proposed waveguide on the geometrical parameters is analyzed using the parallel finite difference time domain (FDTD) algorithm. Numerical results reveal that the extinction ratio and frequency selectivity performance can be adjusted by the structure of the input/output waveguide. The proposed waveguide is capable of suppressing backward propagating interference and greatly improving the total field extinction, which make such plasmonic resonator waveguides more functional.