Abstract. The MgH 2 +20 wt. % BaTiO 3 composites is prepared by ball milling MgH 2 with 20 wt. % BaTiO 3 , and the effect of BaTiO 3 on the hydrogen storage properties of the MgH 2 is investigated. TPD (Temperature-programmed-desorption) results showed that with addition of BaTiO 3 , the onset dehydrogenation temperature of the composite is 270 o C, which is 149 º C lower than that of pure MgH 2 . And the hydrogen absorption / desorption rates of MgH 2 + 20 wt.% BaTiO 3 are 2.21 times and 2.12 times of pure MgH 2 at certain temperatures and hydrogen pressures, respectively. Furthermore, BaTiO 3 additives decreased the dehydriding activation energy of MgH 2 from 116 kJ /mol to 108 kJ /mol. BaTiO 3 plays an effective catalyst role in the hydrogenation / dehydrogenation process of MgH 2 .