This study examined the mediating effects of irrational beliefs on the relationships of middle school students’ autonomy of psychological growth environment and behavioral anger responses(impulsive reaction, verbal aggression, physical confrontation and indirect expression). A sample of 346 first and second year students of middle school participated in the autonomy of psychological growth environment scale, the irrational beliefs scale and behavioral anger responses scale. Pearson’s correlation analysis and regression analysis were performed. The results showed that: ⑴ The relations among autonomy of psychological growth environment, irrational beliefs and behavioral anger responses were significant. The autonomy of psychological growth environment had negative correlations with irrational beliefs and behavioral anger responses. Irrational beliefs produced positive correlations with behavioral anger responses. There were positive correlations among the subtypes of behavioral anger responses. ⑵ There were mediating effects of irrational beliefs between autonomy of psychological growth environment and behavioral anger responses. The effects of autonomy of psychological growth environment on impulsive reaction, physical confrontation and indirect expression were fully mediated by irrational beliefs. However, the effect of autonomy of psychological growth environment on verbal aggression was partially mediated by irrational beliefs. This study demonstrated that irrational beliefs mediate the relationship between autonomy of psychological growth environment and behavioral anger responses.