To evaluate water electrolysis in hydrogen production, a concise model was developed to analyze the current-voltage characteristics of an electrolytic cell. This model describes the water electrolysis capability by means of incorporating thermodynamic, kinetic and electrical resistance effects. These three effects are quantitatively expressed with three main parameters; the thermodynamic parameter which is the water dissociation potential; the kinetic parameter which reflects the overall electrochemical kinetic effect of both electrodes in the electrolytic cell, and the ohmic parameter which reflects the total resistance of the electrolytic cell. Using the model, different electrolytic cells with various operating conditions can be conveniently compared with each other. The modeling results are found to agree well with experimental data and previous published work. Copyright (C) 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.