本研究以協同行動研究法，在自由音樂遊戲之情境中探究教師介入之策略。研究包含三個循環，第一循環以「初探性介入」打開師生互動，並分析出介入角色。此期，幼兒雖然展現豐富的音樂行爲，但缺乏音樂能力之進展。第二循環遂修正爲「目標性介入」，以音高和音長的運用爲介入目標，結果卻無法如期的達成目標。再經資料分析，發現各介入角色之間隱含教師主導與幼兒主導之關係，且在第二循環介入角色多屬教師主導之角色。此外，發現當教師的介入與幼兒遊戲的意圖不一致時，介入就不成功，而進一步釐清遊戲的不同脈絡，並且劃分不同脈絡之主導權。在第三循環以幼兒主導「遊戲脈絡」、教師主導「音樂學習目標」的方式介入，在保有幼兒的遊戲脈絡下，教師隨情境轉換介入角色以達成學習目標，結果2-3歲幼兒在教師的介入中展現高度的音樂能力。

This study investigated teachers' intervention strategies in 2-3 years old children's free music play. A method of collaborative action research consisting of three cycles was conducted. In the first cycle, an approach of exploring intervention opened teachers' and children's interaction to investigate the intervention roles. Children created various music behaviors in the first cycle, but they made little progress in the music ability of pitch and duration. Therefore, the second cycle was revised as purposive intervention to employ pitches and various durations for them to create patterns. Nevertheless, the intervention did not achieve the expected goal. Through data analysis, the relation of children control and teacher control was found in the intervention roles, and the majority of intervention roles in the second cycle were identified as teacher control. When teachers' intervention was not coincided with children's intention of play, conflict occurred. Further analysis clarified various contexts in play. In the third cycle, the intervention was employed under children controlling play context and teacher controlling learning goal. Teachers intervened under children's play context and shifted roles to achieve learning purposes. As a result, children demonstrated high music ability.