隨著全球環境問題日益加劇，氣候變遷已被科學證實對全球環境與人類社會帶來嚴重影響，氣候的議題引起國際高度重視，「淨零碳排」已成為國際社會共同的目標。各國家相繼承諾減碳目標，並積極建立碳交易市場與完善的減碳相關機制，以加速轉型。臺灣為了接軌國際，邁向淨零，於2023年8月7日正式成立臺灣碳權交易所，並於同年12月22日上架首批國際碳權，總計共27家公司響應購買。本研究採用事件研究法，探討臺灣企業購買國際碳權是否會使股價產生異常報酬。並再進一步分析，將購買國際碳權企業分為金融業和非金融業，比較兩者是否會產生差異性之影響。結果發現，企業購買國際碳權對其股價有正向影響，尤其在事件前與事件後幾天出現顯著平均異常報酬，將樣本分類討論發現，短期內非金融業的股價反應較為正面，金融業則偏負向。

With the escalating severity of global environmental challenges, climate change has drawn significant international attention, making net-zero carbon emissions a shared global objective. To align with international trends, Taiwan established the Taiwan Carbon Exchange in August 2023 and released its first batch of international carbon credits later that year, with 27 firms participating. Using an event study methodology, this research investigates whether the purchase of international carbon credits by Taiwanese companies generates abnormal stock returns and compares the short- and long-term impacts on financial versus non-financial firms. The results show that such purchases yield positive market reactions, with significant abnormal returns around the event date. Sectoral analysis further reveals that non-financial firms experience more favorable short-term responses, while financial firms show slightly negative reactions; however, neither sector sustains positive cumulative abnormal returns over the long run.