What was the historical significance of the socialist system formed in China over the course of the twentieth century? To seek to answer this question, this book focuses on Shanghai, the center of modern industry in China since the latter half of the nineteenth century, as a case region, and examines the influence of the introduction of the socialist system in the 1950s on the municipality’s economy through a careful analysis of historical archives and other materials. This chapter introduces the theme, literature, perspectives and methodology, and structure of the book. The main issues this study pursues are, first, how the Shanghai Municipal Government’s control system over the Shanghai economy developed and functioned, and second, how the Shanghai economy was transformed by the implementation of the socialist system. Through analyzing the case of Shanghai, this book explores the impact of the socialist system on the Chinese economy.