本研究為探討「最低稅負制」自財政部研擬草案至立法院通過，對股票市場的影響，進行事件研究，檢測此一增稅法案是否帶給股市負向的影響。同時，本文也分析企業特性與此一累積報酬之間的關聯性，檢測目前享有租稅優惠、高員工配股以及免稅所得的公司是否受到的影響較大。本研究實證結果發現，在最低稅負制政策的演變期間，股票市場普遍反應出負向的累積異常報酬，顯示企業將最低稅負制視為是一個加稅政策。再者，員工分紅高的公司以及擁有較高投資損益的免稅所得公司所受到最低稅負制的影響較大，因此，其股價呈現顯著負向累積異常報酬也較大，且此一反應在電子產業更為顯著。

Using event study method, this paper examines the effect of the policy of implementing Alternative Minimum Tax (AMT) on stock returns of listed companies and investigates the relationship between firm characteristics and abnormal stock returns during the event period of the AMT legislation process. The results of this study show that the stock market reacted to the AMT policy as a tax-increasing event, resulting in negative abnormal returns. Further, Companies distributing greater employee bonus and tax-exempt investment income experienced greater negative abnormal returns during the AMT event period, and the negative impacts of employee bonus and tax-exempt income were more salient for the electronics industry than the other industries.