The development of metal-N-H hydrogen storage system, Li-N-H and Li-Mg-N-H series, is elucidated, especially for their progress in the reaction mechanism and effect of catalysts on reaction kinetics. Subsequently, the most possible reaction mechanism and the reaction limited steps in this mechanism are explored and summed up. Furthermore, we probe into the effects of different catalysts on the reaction steps in these materials, and then we deeply clear up the catalytic interaction between the additives and reaction kinetics. Therefore, this would be a recommendable reference for the research on reaction kinetics in this hydrogen storage system