本研究依據自我決定理論的架構、並以縱貫性的視點來探討初級與高級日語學習者之日語寫作學習動機的異同。考察結果發現兩群學習者均檢測出「價值認知」與「訊息利用」兩項因素，然而，若進一步分析此二項因素的組成題目文，則可發現存在著「純粹的學習動機」與「具有明確目的意識」之質性差異。此外，「勝任感」的平均分數偏低。由於學習無力感會阻礙學習動機的持續發展，為避免學習者對於寫作學習活動望而生畏，建議宜將教學目標著眼於建立學習者自信。最後，此次的考察並未檢測出「自律性」。如何讓學習者脫離依賴教師的學習模式，並正確理解自己才是學習活動的重要主體也是今後努力的課題。

With the architecture of the self-determination theory and from a longitudinal perspective, this study elaborates on the difference in the learning motivation of Japanese writing between the learners of elementary Japanese learning and that of advanced Japanese learning. The research results show that two factors – “value cognition” and “information use” were detected in both groups. However, a further analysis of the title and main body which involved the two factors indicates that there was qualitative difference in “pure learning motivation” and “definite purposeful awareness” between the two groups. Additionally, the average score in “competence” was low. As learning incompetence would retard the continual development of learning motivation, it is suggested that teaching objectives should focus on establishing learners’ confidence in writing. Finally, “self-discipline” was not detected in this study. How to help learners get rid of the teacher-centered learning mode and raise their awareness that they are the main role in learning is an issue to be further explored in the future.