The microstructure of the anode/electrolyte interface is one of key factors to affect the hydrogen production performance of solid oxide electrolysis cells (SOECs). In this paper, a novel interfacial modification method was developed to enhance the active electrode area and the electrolysis performance via preparing a porous YSZ layer on the surface of the dense electrolyte. The effects of YSZ electrolyte pre-sintering temperature, the thickness of dense YSZ electrolyte film and preparation of porous YSZ on the microscopic morphology and the performance of single button cells were investigated. After optimization, a 9 am porous YSZ layer was successfully prepared on the surface of a 4 am dense YSZ electrolyte film with an OCV of 1.072 V at the temperature of 850 degrees C. The results of electrochemical tests showed that the current densities could elevate from -0.681 A cm(-2) to -1.118 A cm(-2) when electrolyzed at 1.5 V under SOEC mode after microstructural modification. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.