The present study explored the relationship between negative life events and reactive aggression among 977 students with ages between 9 to 14-year-old. Reactive and Proactive Aggressive Questionnaire, Rosenberg Self-Esteem Scale, Adolescent Self-Rating Life Events Checklist, and Eysenck Personality Questionnaire(children’s version)-emotional stability dimension were employed in the study. A structural equation model was established to describe the relation between negative life events and reactive aggression,which was mediated by self-esteem and emotional stability. The results showed that negative life events directly affected the formation of reactive aggression, and indirectly affected reactive aggression by changing the emotional status. That is, when negative life events occurred, the emotional status tended to be unstable, which led to a higher level of reactive aggression. Besides, negative life events also resulted in the instability of emotional status by reducing the level of self-esteem, which gave rise to a stronger level of reactive aggression as well.