In this study, the properties, applications, technological barriers, and future projection of magnesium and magnesium based materials in fuel economy and energy production were evaluated. Mg lowers fabrication and joining costs, substitution by lightweight materials enable weight savings, in addition lifetime fuel costs and CO 2 emission are reduced. Studies state that reducing the automotive weights by a certain amount will result in a similar reduction in fuel consumption and CO 2 emissions. Most power systems, either renewable or nuclear, provide solutions for electricity production, but to date, there is no satisfactory substitute for liquid fossil fuel for use in transportation (cars, airplanes, and the like) due to environmental reasons or security of supply. A resent approach to this problem is to use hydrogen as fuel. Researches on Magnesium-Air Fuel Cell (MAFC) Technology resulted in new and improved technologies which have advanced the magnesium-air fuel cell to commercialization. The MAFC approach to an alternative energy source is the development of a powerful, reliable and environmentally friendly non-toxic fuel cell that generates energy using magnesium. From the results of the resarches it is concluded that magnesium applications reduce CO 2 emission, and fuel costs.