Abstract: The research was aimed to explore the relation between alienation, self-esteem and security among middle school students. Adolescent Students Alienation Scale, Security Questionnaire and SES were used to measure the level of alienation, security and self-esteem of 444 middle school students. The results show that: The level of alienation and security were significantly different across grades(P<0.001). Among the dimensions of alienation, environmental alienation scored the highest score while interpersonal alienation the lowest. There is significantly different relationship between alienation, security and self-esteem(P<0.01). The result of regression analysis indicates that social alienation can well predict security, with the explanation reaching 58.9%. Self-esteem and alienation can predict security to some extent, and self-esteem can partially mediate the effect of alienation and security(P<0.001)