Nowadays, hydrogen is being utilized massively in industries as a clean fuel. Displacing of hydrogen due to unique chemical and physical properties has adversely affect on pipeline network, hence increases the potential risk of explosion. This study was carried out to determine the flame propagation of hydrogen/air and hydrogen-methane/air mixtures in pipeline. A 90 degrees pipeline with LID ratio of 40 was used. Pure hydrogen/air mixture with equivalence ratio, phi = 0.13, 0.17, 0.2, 0.24, 0.27 and 0.30 were used in this work. Different composition of hydrogen methane air mixtures were tested in this study i.e. 3% H-2 + 97CH(4), 4%H-2 + 96CH(4), 6%H-2+ 94CH(4) and 8%H-2 + 92CH(4). All mixtures were operated at ambient condition. The results show that bending is the critical part of pipeline and higher concentration of hydrogen can affect on maximum overpressure, flame speed and temperature rise of both pure hydrogen/air and methane-hydrogen/air mixtures. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.