perties of plasmonic waves of graphene on a conducting substrate are discussed based on the classical electrodynamics and linearized hydrodynamic model. General expressions are given and illustrated graphically for the dispersion relation, power flow, energy density and energy transport velocity of the plasmonic waves. The numerical results show that acoustic plasmon mode of the system has a group velocity that can be made arbitrarily close to the graphene Fermi velocity by tuning the graphene–metal distance or graphene sheet carrier density.