Crude oil, natural gas, and coal are the main sources of energy supply in our daily lives, particularly in transportation. As the world's energy demand is increasing significantly, environmental friendly energy sources, such as solar and wind energy, are essential and hydrogen is the best energy carrier for these kinds of energy sources. However, hydrogen must be stored in the required methods and materials which have been specified by the US Department of Energy and magnesium is one of the most promising candidates for hydrogen storage. The object of this book is enhancement of the hydrogen storage properties of MgH2 using different kinds of catalysts and ball-milling methods. Preparing binary composites such as MgH2-SiC and MgH2-BCC nano-composites and also ternary samples such as MgH2-SiC-Ni and MgH2-BCC-CNT specimen by both planetary and magneto ball milling have shown significant improvements in hydrogen sorption properties of MgH2. The methods and results in this book could help shed some light on the area of hydrogen economy and would be useful for post graduate and graduated students in this area, experimental physicists, and material scientists