This study examined trajectories of shyness-sensitivity and the contributions of peer relationships to these trajectories in Chinese children. Participants were 1061 school-age children (537 boys), initially in fifth grade (Mage = 11years), in China. Longitudinal data on shyness-sensitivity were collected from peer assessments once a year for four years. In addition, peer nomination data on peer acceptance-rejection and mutual friendship were collected in the initial study. Four distinct shyness-sensitivity trajectories were identified: Low-Stable, Low-Increasing, Moderate-Decreasing, and High-Stable. Children with high peer acceptance scores were more likely to be in the High-Stable and Moderate-Decreasing trajectories than in the Low-Stable and Low-Increasing trajectories. The analysis of predictors of the within-trajectory growth rate indicated that children who were more liked by peers increased their shyness-sensitivity more slowly within the Low-Increasing trajectory and that children with mutual friendship involvement decreased their shyness-sensitivity more slowly within the Moderate-Decreasing trajectory. The results suggested that positive relationships might serve to attenuate developmental changes of shyness-sensitivity within these trajectories. The results were discussed in the Chinese context.