--- - |2 This study investigated the development of relational aggression (RA) in a sample of Chinese youth (N = 2,274, 52% boys) from fourth (Mage = 10.27 years) to ninth grade. Using latent class growth analysis, four trajectories were identified for both peer‐ and teacher‐rated RA: a no aggression trajectory, a low‐increasing trajectory, a moderate‐decreasing trajectory, and a chronically high trajectory. Chronically high RA showed a chronicity effect on adolescent peer acceptance, rejection, and rule‐breaking behaviors. Adolescents showed worse adjustment as RA increased, but they did not necessarily evidence significant improvement in adjustment even if their RA decreased. Findings reveal the maladaptive nature of RA and highlight the importance of considering cultural context in understanding RA. - Child Development, EarlyView.