The BaCo0.7Fe0.3-xTaxO3-delta (BCFT, x = 0-0.150) membranes were synthesized by the conventional solid-state reaction process for hydrogen production by partial oxidation reforming of coke oven gas (COG). The influences of tantalum doping in BCFT oxides on phase structure stability and oxygen desorption property were systematically investigated by XRD, H-2-TPR, O-2-TPD and TG-DSC. The experimental results indicated that the tantalum introduction could decrease slightly the oxygen permeability of BCFT membranes, but significantly improve the phase structure stability at high temperature in reducing atmosphere. The oxygen permeation flux of BaCo0.7Fe0.225Ta0.075O3-delta with 1.0 mm thickness membrane is as high as 18.04 ml min(-1) cm(-2) at 900 degrees C under Air/COG gradient. Crown Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.