This book focuses on transmission systems for pure electric and hybrid vehicles. It first discusses system development and optimization technologies, comprehensively and systematically describing the development trends, structures and technical characteristics, as well as the related technologies and methods. It highlights the principles, implementation process and energy management of the power transmission system based on the pure electric and hybrid mode management method, and examines the reliability and NVH characteristic tests and optimization technologies. Combining research theory and engineering practice, the book is a valuable reference resource for engineering and technical professionals in the field of automobile and related power transmission machinery as well as undergraduate and graduate students.