Flow distribution among microchannels is a fatal factor affecting the performance of laminated microchannel reactors for hydrogen production. Homogeneous flow strongly depends on the structural design of the microchannel reactor. The present work concentrates on improving the flow distribution in microchannel reactors for hydrogen production by optimization of the structural design. An innovative A-type microchannel reactor for hydrogen production with one inlet/two outlets was developed and analyzed. The equivalent electrical resistance network model was used to calculate the flow distribution in the microchannel reactor which was validated by computational fluid dynamics (CFD). The influences of structural parameters on flow distribution in the A-type were investigated quantitatively. The calculated results showed that longer microchannels with a higher aspect ratio and a small side length in the manifolds were beneficial for attaining uniform flow distribution in the A-type microchannel reactor. Furthermore, it was found that flow distributions among the microchannels in the A-type were much more uniform than those in the conventional Z-type microchannel reactor with one inlet/one outlet. Finally, an optimization strategy was proposed to optimize the manifold geometries to obtain a comparatively even flow distribution among microchannels. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.