This paper reports a comparative study of synthesizing Mg(BH4)(2) by mechanically milling Mg + B, MgH2 + B and MgB2 powders following hydrogenation under hydrogen atmosphere. It has been shown that the milled Mg + B and MgH2 + B powders consisted of magnesium hydride and boron, while the milled MgB2 powder remained unchanged during the milling process. TEM, Raman spectra and TPD measurements confirmed the formation of amorphous Mg-B-H compounds in the milled Mg + B and MgH2 + B powders, which could be Mg(BxHy)(n) moieties. The total hydrogen desorption amounts after 3 h were 3.7 wt.% and 3.9 wt.% for the milled Mg + B and MgH2 + B powders respectively, whereas the milled MgB2 showed little apparent hydrogen desorption. After a hydrogenation process was carried out, the further hydrogenated MgB2 powder was found to contain the amorphous Mg-B-H compounds and could release 0.25 wt.% hydrogen. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.