The failure of membrane electrode assembly (MEA) relates to the fuel consumption for proton exchange membrane fuel cell(PEMFC). In this study, a complete 3-D computational model, including nine layers of the integrated fuel cell system, was developed to investigate the influences of depth-reduced channels on hydrogen consumption. Simulation results showed that the different combinations of depth caused dissimilar pressure profiles, pressure drop, and distribution of hydrogen concentration in the depthreduced channels, and thus resulted in the variations of the current density and the hydrogen consumption. The maximum hydrogen mass flux in MEA was located at the area of channel entrance for all channels. This implied that the serious degradation of MEA always occurred around the channel entrance. In addition, a depth-reduced channel with a shorter and deeper front section was able to reduce the maximum hydrogen mass flux by about 3-4% with losing current density about 2%. These results suggest that a depth-reduced channel with a shorter and deeper front section can delay the serious degradation of MEA to prolong the lifetime. Copyright (C) 2007 John Wiley & Sons, Ltd.