This open access book is a new study by the Institute for Contemporary China Studies at Tsinghua University, condensing the new achievements of the Institute’s national policy research. Taking "common prosperity" as the theme, the book elaborates the historical background, ideological sources and theoretical connotation of common prosperity. It reviews the theoretical and practical innovations of common prosperity in three historical periods: the socialist revolution and construction period, the new period of reform and opening up and socialist modernization, and the new era of socialism with Chinese characteristics. It discusses the development goals and practical approaches for China to build a society of common prosperity by 2035, analyzes the development basis and challenges China faces in promoting common prosperity, and puts forward the overall goals and quantitative indicator system for achieving common prosperity in the new era, as well as major tasks, policy logic and pathway for promoting common prosperity. The book also looks into the great significance and world significance of China's realization of common prosperity. Policy interpretation in the book is thorough, and the data is accurate, with authoritative, professional and forward-looking perspectives. This is an open access book.