Objective To explore the effect of mindfulness training on mental health of elite athletes and its possible mechanism.Methods Totally 462 Chinese elite athletes(Mage=18.16,SD=3.14,Range=12～28,44.8%female)were conducted a cross-sectional questionnaire survey.SPSS23 was employed for data statistical analysis,and the mediation model was tested through the Bootstrap program of the extension program PROCESS.Results Mindfulness significantly and negatively predicted anxiety(β=-0.386,P<0.001),depression(β=-0.342,P<0.001),and poor sleep quality(β=-0.324,P<0.001),but significantly and positively predicted training&competition satisfaction(β=0.432,P<0.001)and psychological well-being(β=0.399,P<0.001).Moreover,mindfulness showed significant effects on anxi-ety,poor sleep quality,and satisfaction to training and competition through experiential acceptance,cognitive defusion,and decentering.However,it performed significant impacts on their depression and psychological well-being only through experiential acceptance and cognitive defusion.Conclusion Mind-fulness directly predicts negative reactions such as anxiety,depression and poor sleep quality,as well as positive ones including training and competition satisfaction and psychological well-being in elite ath-letes.Moreover,it has indirect effects on anxiety,poor sleep and training and competition satisfaction through experiential acceptance,cognitive defusion and decentering,together with on depression and psychological well-being through the former two factors.