The effect of dopant Ce on the dehydrogenation properties of crystalline NaAlH4 is investigated by employing density functional theory.The result indicate that the Ce mainly influence the electronic structures of the adjacent atoms, the dehydrogenation effect is significantly sensitive to the occupation behavior of Ce atom, the removal energy of hydrogen is dramatically decreased, and the dehydrogenation performance of the doped NaAlH4 is conspicuously improved. The Ce-H and Ce-Al interaction weaken the Al-H bonding strength, which is main factor that enhance the dehydrogenation performance of the Ce-doped NaAlH4 nanocrystal.Graphical Abstract: