The samples Mg–10wt.% (Fe 2 O 3 , Ni, MnO) was prepared by mechanical grinding under H 2 (reactive mechanical grinding) under the optimum conditions, studied previously, for the preparation of the sample Mg–10wt.% Fe 2 O 3 using purchased Fe 2 O 3 . The sample Mg–10wt.% (Fe 2 O 3 , Ni, MnO) as milled absorbed 4.15wt.% hydrogen at 593K under 12bar H 2 for 60min. Its activation was accomplished after two hydriding–dehydriding cycles. The activated sample absorbed 4.02wt.% hydrogen at 593K, 12bar H 2 for 60min desorbed 3.03wt.% hydrogen at 603K, 1.0bar H 2 . Hydrogen-storage capacity was 5.34wt.% under 12bar at 593K (from P–C–T curve). The equilibrium plateau pressure is about 1.5bar H 2 . Mg–10wt.% (Fe 2 O 3 , Ni, MnO) has lower hydriding rate than Mg–10wt.% Fe 2 O 3 by spray conversion, but it has higher dehydriding rate than Mg–10wt.% MnO and Mg–10wt.% Fe 2 O 3 by spray conversion.