Currently, non-oriented electrical steel sheets are mainly used as soft magnetic materials for motor cores. Low-loss soft magnetic materials have attracted attention particularly in electric vehicles for the purpose of further increasing efficiency. This chapter presents the properties of amorphous alloys, nanocrystalline alloys and advanced electrical steel sheets, as well as the evaluation results of a prototype radial gap motor with an amorphous alloy core and a high-Bs nanocrystalline core.