Urbanization in China and technology innovation in the United States are two major events in contemporary times, which will have enormous impact on the future development of human history. Urbanization is a process of transformation from rural life to a life in cities. It has been an engine of the growth in China since the economic reform started in 1978 and will be a crucial driving force of the economic and social changes in the twenty-first century. China was a rural society until the recent past. About 80 percent of the population were still living in the countryside in the late 1970s, not much different from the late Qing Dynasty (1616-1911). A rapid change has happened since then. Hundreds of millions of peasants poured into the cities over the past 30 years and over half of the population live in urban areas now. The suddenness of the change seems to defy some economists' belief that 'nature does not take great leaps' (Mokyr 2000; Darwin 18 59). How did this happen? What is the driving force of this process? What are the obstacles to this process? What is the meaning of this urbanization to China and the world? This book is an attempt to answer these questions.