Despite many studies on the situation of children in China, there is a dearth of a proper and complete study of the conditions in which these children live. This book, based on national household survey data, offers a comprehensive analysis of the conditions. This book covers all major aspects of child development, including physical health, mental and psychological well-being, and their cognitive and educational development. It focuses on examining the developmental disparities between children of rural and urban regions and those with different living arrangements, for instance, left-behind children and migrant children. It reveals variations in the ecological contexts of these children i.e., different conditions of their families and communities that may have contributed to the children's developmental trajectories.