In summary, we have presented an H-shaped plasmonic coupler which is based on the metal-dielectric-metal based nano-slot waveguides. The analyses of the plasmonic coupler have been carried out by using the volume integral equation method. The parametric studies of several geometry parameters have also been performed. From the results we obtained, it is found that light can be efficiently coupled into different ports and the operating wavelength of the coupler can be effectively tuned by varying the ratio between width a and b.