Ring theory has been developing through the interaction between the investigation of its own algebraic structure and its application to many areas of mathematics, computer science, and physics among others.This volume consists of a collection of survey articles by invited speakers and original articles refereed by world experts that was presented at the fifth China–Japan–Korea International Symposium. The survey articles provide some ideas of the application as well as an excellent overview of the various areas in ring theory. The original articles exhibit new ideas, tools and techniques needed for successful research investigation in ring theory and show the trend of current research.The articles cover all of the most important areas in ring theory, making this volume a useful resource book for researchers in mathematics — both beginners and advanced experts.