Abstract:The present study aimed to investigate the relationship between junior high school students’ career maturity and their positive emotion as well as the mediating role of self-esteem. Questionnaires were administrated to 692 junior high school students from Beijing and Wuhan. Results showed that junior high school students’ career maturity positively predicted their positive emotion. Self-esteem worked as a full mediator between the predictors including career self-knowledge, confidence, stability, and the outcome of positive emotion. Career maturity also severed as a partial mediator between the predictors including career world-knowledge, initiative, and the outcome of positive emotion. It is therefore suggested that junior high school students’ career maturity could significantly impact their positive emotion through the mediating role of self-esteem.