This book comprehensively discusses the effects of digital technology on the way work is disseminated and the resulting challenges concerning the fair use of copyright. It also analyzes so-called fairness by examining theories on the system of fair use, demonstrating the “system changes that will be brought about by technological changes” from the perspective of economics, i.e., the problem of modification faced by the system of fair use of copyright.Exploring the nature and function of fair use and repositioning the fair use system, the book proposes a better design for China’s system of limitation on copyright and a readjustment of the copyright system.Lastly, in addition to analyzing the reconfigurations of fair use from an economic standpoint, the book describes in detail the interactions between legal systems and cultures.