The amorphous alloys of Zr57Al10Cu15.4Ni12.6Nb5 and Zr55Cu30Ni5Al10 were melted and cast under the gaseous mixture of hydrogen and argon. The effects of hydrogen on glass plasticity of the two bulk metallic glasses were studied. Surprisingly, it was found. that hydrogen addition can increase the glass plasticity significantly. The large plasticity of glass is attributed to the large amount of free volume induced by hydrogen addition, which could make this melt hydrogenation method to be a promising new way to improve plasticity of amorphous glass. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.