From a sociological perspective, this book explores issues related to population mobility, family pensions, and the lives of workers and peasants during the 70 years of urbanization since the founding of New China from the perspectives of population, pension security, employment structure transformation, and social insurance systems, thus exploring the deep logic behind China's successful experience. The relevant issues studied in this book are a systematic summary of the experiences and lessons learned from social reforms since the founding of the country and also provide guidance for the future direction of social development and change.