For a vertically vibrating box filled with Cu grains or glass beads, we study power of dissipating energy of the granular system, by measuring acceleration of the box and force acting on it. It is found that for a given vibrating strength the power displays a wide peak structure centered at several tens Hz as vibrating frequency varies, and for a given frequency its variation with the strength obeys a power law, with an exponent smaller than that of a forced harmonic oscillator model 2. The results are considered to be useful for determining magnitudes of transport coefficients of granular liquids and gases, as well as difference in dissipative energy between their different dynamic patterns.