The hydrogen storage properties of LiBH 4 /MgH 2 ball milled with Pd nanoparticles were investigated. By introduction of Pd nanoparticles, the initial dehydrogenation temperature of the composite decreases from 340 to 260°C and the total weight loss reaches up to 8.0wt.% below 400°C. Rehydrogenation results show 7.9wt.% hydrogen can be rehydrogenated from the dehydrogenated product at 400°C under 35atm of hydrogen for 6h. XRD analysis demonstrates that the hydrogen desorption of the Pd doped LiBH 4 /MgH 2 mixture mainly includes two steps: first, at temperature above 260°C, magnesium hydride reacts with Pd nanoparticles to generate Mg 6 Pd and the decomposition of MgH 2 ; and then, above 350°C, magnesium reacts with LiBH 4 to form MgB 2 and LiH.