In this work, Mg50La20Ni30 bulk metallic glass (BMG) was prepared and its hydrogen absorption/desorption behavior was studied. The amorphous structure was found to be retained after gaseous hydrogenation. The T-g and T-x of the hydrogenated Mg50La20Ni30 BMG was 561 K and 619 K respectively, much higher than the corresponding value of 463 K and 504 K of the unhydrogenated sample. Mg50La20Ni30 BMG absorbed 0.73 and 1.85 wt% hydrogen within 1 h at 313 K and 423 K respectively, which was higher than that of ball-milled Mg2Ni alloy. Mg50La20Ni30 BMG exhibited an equilibrium hydrogen absorption plateau with a pressure of 0.07 MPa in pressure-composition isotherm curve at 423 K. It suggested that Mg-based BMGs are promising materials for hydrogen storage applications. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.