The processes of chemical synthetic method to prepare Mg2Ni hydrogen absorbing alloy were studied. Ni was first deposited onto Mg by stirring DMF which contained Mg particle and Ni ions. Mg2Ni was obtained by heating the Ni-deposited Mg subsequently. Here the stirring condition which was among the most important factors influencing the alloy formation was mostly studied. It seemed that there were two steps in the stirring process for the alloy formation, i.e. the Ni deposition (adsorption) onto Mg and the precursor formation. The stirring speed and temperature affected the two steps intricately and the different behaviors were observed at the stirring temperature of 40 degrees C from the cases at 20 degrees C and 80 degrees C. The obtained alloy samples had rather the mixture forms and exhibited the hydrogen absorption of similar to 3 wt% at above 250 degrees C. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.