Society forges ahead in the process of solving various contradictory problems and it is ceaselessly innovating. It is the desire of mankind to use computers and computing networks to help deal with contradictory problems and to conduct innovative activities. Using formal models to discuss object extension and the possibility of change, as well as the rules and methods for innovation, Extenics is applied to solving contradictory problems and has become the basic theory, method and instrument to achieve this goal. In the 30 years since the foundation of Extenics, researchers have built relatively complete theoretical systems -'extension theory', studied formal and modeling innovation methods -'extension innovation methods', and launched the applications in various fields such as information, design, automation and management etc. -'extension engineering'. Extension theory, the extension innovation method and extension engineering jointly constitute the new discipline-Extenics. At the same time, the practical activities of engineering technology and management promote the integration of various innovation methods such as TRIZ and brainstorming etc. This book collects together, from scholars in various fields, the research achievements in Extenics and innovation methods, in order to facilitate and promote the development of Extenics and the various innovation theories and methods, as well as to improve its innovative capacity in academic and business circles.