||High performance light alloys have become more and more attractive for the wide appreciations such as automotive vehicles, rapid transportation trains, aircraft and aerospace materials. It is, therefore, greatly required to improve alloy properties, e.g. mechanical strength and ductility. To achieve the various requirements for the alloys the control of alloy compositions and optimized processing is essentially important. In this paper, recent advances in the alloy designing, fabrication processes and microstructural analyses for the wrought and cast aluminum and magnesium alloys are presented. Especially, the nanostructure control and analyses in the atomic scale are introduced.