In this paper, oscillatory and steady flows of water through two different porous media consisting of mono-sized stainless steel balls are studied experimentally. The friction factors, permeabilities and inertial coefficients are determined experimentally for steady and oscillating flows. The correlations of maximum friction factor for oscillating flow are presented and they are compared with those of steady flow. Permeability and inertial coefficient of porous media subjected to the oscillating flow are obtained by using the correlation equations of maximum friction factor. Pressure variations calculated by using these coefficients are in good agreement with experimental data. It is experimentally shown that the permeability and inertial coefficient of oscillating flows are greater than those of steady flow in the same range of Reynolds number. (C) 2011 Elsevier Inc. All rights reserved.