The discovery of new hydrogen storage materials has greatly driven the entire hydrogen storage technology forward in the past decades. Magnesium hydride, which has a high hydrogen capacity and low cost, has been considered as one of the most promising candidates for hydrogen storage. Unfortunately, extensive efforts are still needed to better improve its hydrogen storage performance, since MgH_2 suffers from high operation temperature, poor dehydrogenation kinetic, and unsatisfactory thermal management. In this paper, we present an overview of recent progress in improving the hydrogenation/de-hydrogenation performance of MgH_2, with special emphases on the additive-enhanced MgH_2 composites. Other widely used strategies(e. g. alloying,nanoscaling, nanoconfinement) in tuning the kinetics and thermodynamics of MgH_2 are also presented. A realistic perspective regarding to the challenges and opportunities for further researches in MgH_2 is proposed. The discovery of new hydrogen storage materials has greatly driven the entire hydrogen storage technology forward in the past decades. Magnesium hydride, which has a high hydrogen capacity and low cost, has been considered as one of the most promising candidates for hydrogen storage. Unfortunately, extensive efforts are still to improve improve its hydrogen storage performance, since MgH_2 suffers from high operation temperature, poor dehydrogenation kinetic, and unsatisfactory thermal management. In this paper, we present an overview of recent progress in improving the hydrogenation / de-hydrogenation performance of MgH_2, with special emphases on the additive-enhanced MgH_2 composites. Other widely used strategies (eg alloying, nanoscaling, nanoconfinement) in tuning the kinetics and thermodynamics of MgH_2 are also presented. A realistic perspective regarding to challenges and opportunities for further researches in MgH_2 is proposed.