本文旨在以轉化能動性為概念工具，探究如何有助於對教師社群集體活動之理解。活動理論的轉化能動性，採用六種轉化行動：抵抗、批判、顯化、構想、定案與實際行動，勾勒團體成員在對話中轉化能動性的變動內涵。然而，以「單一發言」為轉化行動的編碼分析單位，會漏看成員相互對話的動態轉變歷程；因此，本研究發展以「事件」為編碼分析單位。研究發現，老師之間看似和諧的社群對話中，隱藏著意見衝突的協商處境，透過事件為分析單位，揭露因內隱衝突而蘊生的轉化策略。本研究對轉化能動性概念工具的再探究有兩個層面的突破：第一、發展更契合對話情境之分析單位「轉化事件」，第二、揭露比轉化行動層級更適切的「轉化策略」層級，展現教師集體轉化能動性的清晰圖像。本文對當前新課綱推動之下，正蓬勃發展之教師社群運作，提供研究面與實務面的具體建議。

This study aims to explore how transformative agency as a conceptual tool is conducive to a better understanding of a teacher-community activity. Based on cultural-historical activity theory, transformative agency in a collective discourse includes six types of agentive action: resisting, criticizing, explicating, envisioning, committing, and taking consequential action. These agentive actions are used to show the transformative agency in a collective discourse. However, using a speaking turn as the unit of analysis suggested in the theory, might overlook the dynamic process of a responsive dialogue among community members. Due to the aforementioned analytical limitation, the present study suggests using a “transformative event” as the unit to analyze the transformative agency. The research findings reveal that the seeming harmonious dialogical exchanges in the teacher community might involve the process of hidden conflict and negotiation. With the “event” used, hidden conflict may give rise to transformative strategies, which could be an essential agency in facilitating changes and reform of a community. There are two contributions found in this study: a) the development of “transformative event” as the unit of analysis to understand the dialogical context of a teacher community; b) the revelation of “transformative strategy” delineates the collective effort of teachers’ transformative agency. With the ongoing reform of the new curriculum and the flourishing development of teacher community, this paper offers concrete suggestions for future research and practice.