Abstract: The directional coupling of long-ranging channel plasmon polariton in the V-groove plasmonic waveguides covered with ultra thin metal film was studied. By calculating the modes' distributions, confinement factors and propagation lengths of the odd and even modes in different waveguide distances were acquired. The relationship between coupling length and maximum crosstalk with different waveguide distances were calculated. It is found that the coupling length is smaller than the propagation lengths of any mode in small waveguide distance, and the coupling length becomes larger and the maximum crosstalk becomes smaller as the waveguide distance increases. The investigation of the directional coupling in the V-groove plasmonic waveguides with ultra thin metal film is important to its applications in the photonic integrated circuits.