Mental toughness is one of the most important efficient psychological characters between elite athletes and efficient factors understanding have much importance. The aim of the present study was to investigate the relationship between emotional intelligence and mental toughness in elite and amateurs Taekwondo athletes. Present study research method was correlation and causative-comparative Participants were 140 taekwondo athletes (70 elite and 70 amateur athletes) that they chose based on random sampling from Iranian Taekwondo populations. This population completed the scals of emotional intelligence Schutte et al (1998) and mental toughness sheard & et al (2009). The data was analyzed by anova, Pearson correlation and multiple regressions. The results showed a significant relationship between emotional intelligence and mental toughness, Also results of Anova test showed that there was a significant difference between elite and amateurs of taekwondo athletes in both emotional intelligence and mental toughness. In addition, elite taekwondo athletes got higher scores finally; regression analysis showed that emotional intelligence indexes predict 57 percent of mental toughness variance (P<0.001). In general, emotional intelligence is a predictor factor in mental toughness. Therefore, designing and implementing the effective training programs can help to boost and develop mental toughness.