The book studies the educational needs of two disadvantaged groups of children in China (left-behind children in rural areas and migrant children in urban areas), aiming to optimize the social support system so that these disadvantaged children can realize their full potential. The author conducts two separate researches and introduces the research background, methodology, related theories and advanced theories. Main difficulties of left-behind children and migrant children include parents' lack of attention to their children's mental health, teachers' lack of expertise in working with these two groups of children, and a lack of collaboration between schools and NGOs. It suggests promoting systematic reform, helping parents to develop effective parenting skills, and establishing positive interactions among the stakeholders of social support for these disadvantaged children. The book will be of interest to people who work with left-behind children in rural areas and those who work with migrant students in urban areas, including teachers, school administrators, local educational authorities, community-based service providers, and provincial and central departments of education.