目的：探討大專棒球選手之運動熱情、教練－選手關係對心理堅韌性的預測關係，並以結構方程模式驗證這些變項關係的適切性。方法：採用問卷調查法，以232名一般組大專棒球選手為參與者（20.31 ± 1.75歲，球齡4.97 ± 2.97年），於休息狀態填寫包括運動熱情、教練－選手關係和心理堅韌性等問卷資料。資料收集後，以多元同時迴歸和結構方程模式進行分析處理。結果：強迫式熱情與調和式熱情能夠正向預測心理堅韌性的積極奮鬥；強迫式熱情、教練與選手關係的親密性與互補性越高，心理堅韌性的抗壓性則越高；但教練與選手關係的承諾感越高時，心理堅韌性的抗壓性則越差。調和式熱情和教練與選手關係的承諾感越高，心理堅韌性的忍受傷痛程度越高。結構方程模式的分析也顯示，觀察資料適度的支持運動熱情、教練－選手關係能有效預測運動員的心理堅韌性。結論：對教練而言，引導運動員發展對專項運動的熱情，以及營造一個具有支持性的教練和選手互動關係，可以有助於運動員發展出較佳的心理堅韌性。 Purpose: This study was to examine the predictive effect of sport passion and coach-athlete relationship on mental toughness among college baseball players, and identify the casual relationships among these variables using structural equation modeling. Method: Two hundred and thirty-two college baseball players who competed at the level of Division Ⅱ were recruited to complete a battery of questionnaires regarding sport passion, coach-athlete relationship, and mental toughness in a resting setting. Data obtained were analyzed by the multiple regression analyses and structural equation modeling. Results: The results indicated that both compulsive and harmonious passion could positively predict effort and self-discipline, a component of mental toughness. Further, compulsive passion, closeness, and complementarity could positively predict coping ability, whereas commitment negatively predicted coping ability. In addition, compulsive passion and commitment positively predicted pain endurance. Moreover, the fit index of overall model and internal structure indicated that the relationships hypothesized in this study validated the observed data. Conclusion: The findings suggest that coaches should inspire athletes' passion toward specific sports and create a supportive coach-athlete interaction, which would enhance the development of mental toughness for athletes.