|This study aims to examine effects of mixed martial arts(MMA) trainees` self-esteem on their stress and mental health. To this end, 330 MMA trainees in MMA gymnasiums were selected as study subjects but a survey of 302 among them was only conducted. The collected data carried out factor analysis and reliability analysis to verify construct validity and to analyze the result, descriptive statistics, correlation analysis and multiple regression analysis were conducted. As the result, effects of MMA trainees` self-esteem on stress were negative self-esteem, followed by positive self-esteem. Effects of MMA trainees` self-esteem on emotional health showed that fear/anxiety, depression, somatization, and compulsion had impact on both positive and negative self-esteem. In addition, effects of MMA trainees` stress on mental health had significant impact on all the fear/ anxiety, depression, somatization, and compulsion.