This book summarizes the thermodynamics and kinetics of Mg-based storage materials and introduces recent progress, including alloying, adding catalysts/composites and nanosizing on Mg-based hydrogen storage materials. The content describes the fundamental theories of hydrogen storage materials and reviews the key achievements in applications. The targeted audience of this book includes scientific/engineering researchers, technicians, lectures, entrepreneurs, and investors at all levels related to hydrogen energy, materials, chemicals, etc. This book can also be used as a textbook for senior undergraduate and postgraduate students in hydrogen energy, materials, and chemical engineering.