The concept of modern childhood first appeared in the industrial western countries. It reflects the modern way of thinking about children and their life since the Enlightenment. The concept of modern childhood focuses on the difference and the antagonism between children and adults. It builds up the linear mode of child development and leads to the "standardized" childhood. The concept of modern childhood derives from the modern logic of dichotomy, which is restricted by the biology-based research perspectives and consolidated by institutionalized schooling and the changing modern family life. Based on the immaturity of children's physical development, the concept predicts the deficiency in children's social skills, which isolates the marginalized child from the adult world. How to define the concept of childhood is dominated by adults, while the diverse morphology of childhood tends to be ignored and the voice of children is not heard.