This article provided an overview on children's relational aggression, which is defined as a behavior that harms others through damage (or the threat of damage) to their peer relationships (e.g., angrily retaliating against a peer by excluding her/him from one's play group). It was suggested that (1) longitudinal research should be conducted to enhance our understanding of developmental manifestations of relational aggression, stability of relational aggression, and the relation between relational aggression and social-emotional adjustment, (2) as relational aggression has unique nature and functions, a reconsideration of past theoretical and empirical models of aggression is warranted, and (3) research of intervention with relational aggressive children is needed.