After reviewing literature on self-criticism, optimism and athletes' burnout, this study formulated two hypotheses: (1) self-criticism might have a positive influence on athletes' burnout; however, (2) optimism would have a negative influence on athletes' burnout. In order to test the two hypotheses, this study used a cross-sectional experiment design to collect data. Participants were 469 high-school athletes with a mean age of 16.10 (SD=1.56) who were administered with a self-criticism scale, a life-orientation test and a Eades athlete's burnout inventory. Data were analyzed by hierarchical regression and the results showed hypothesis1 only received little support; however, hypothesis 2 was supported. Implications and application were discussed and practical suggestions were made for future research.