The Mg-bearing Al-Ga-In-Sn alloy with more stable hydrogen generation rate during hydrolysis reaction was synthesized, which is great suitable for the on-board hydrogen supply applications. The test results show that the hydrogen release rate of the Mg-bearing alloys could be effectively controlled. In particular, when the Mg dosage is 0.5 wt.%, the average hydrogen generation rate can even be reduced to 2.1 ml/min.g, while the total energy conversion efficiency of Al has not been affected and still reaches to nearly 100%. Further analysis shows that the reduction of hydrogen production rate during the Al-water reaction process is closely related to the changes of the phase compositions and the microstructure of grain boundary phase (GB-phase) particles in these alloys. Moreover, the electrochemical tests further clarify the reactivity of the alloys with different Mg dosage. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.