This thesis is a study of the cultures of children. Its principal perspective is sociological, though it draws heavily on the substantial body of work on children within the field of psychology. It also engages with work within the field of cultural studies, and in particular studies of youth cultures. The Gramscian perspective which informs much of the work in this area provides a theoretical framework for conceptualising children's cultures as partly autonomous from, but powerfully shaped by, ideologies and structures in the wider society. The study makes special reference to issues of 'race' within children's cultures. A theoretical framework derived mainly from studies of 'race' and youth within the 'cultural studies' tradition provides the context for a critical engagement with work on social identity within the field of social and cognitive psychology. The research on which the study is based was conducted with children in mainly- white primary schools. Most of them were aged 10 and 11. A smaller-scale follow-up study was carried out two years later when the children were at secondary school. The study adopts a qualitative methodology in order to explore the peer relationships and social interaction of children, and the extent and ways in which it may become racialised. Its findings confirm and extend previous research on friendship and conflict in children's cultures. They contribute to an understanding of 'race' in children's lives by identifying the principal forms it takes and situating them within the cognitive and social processes of children's cultures. The distinction between the expressive and instrumental functions of name-calling and other forms of racist behaviour provides the basis for a theorisation of the 'thematic' ideologies of 'race' which embody children's beliefs and the 'interactional ideologies' which govern peer interaction, and the complex relationships between them.