本研究旨在以投資大眾的角度出發，研究正、負面企業社會責任事件宣告如何影響投資者的投資決策，進而影響股價產生異常報酬。實證結果發現，正面企業社會責任事件宣告將產生顯著為正的股價異常報酬；負面企業社會責任事件宣告則將產生顯著為負的股價異常報酬。另外，本研究針對負面企業社會責任事件所產生的累積異常報酬建立了複迴歸模型，探討企業規模、企業所屬產業及負面企業社會責任事件宣告之消息種類與該累積異常報酬是否存有關聯性，實證結果發現，大型企業、宣告之消息種類屬於資訊公告問題者，與該累積異常報酬呈現顯著負相關；企業屬於高汙染產業者與該累積異常報酬呈現顯著正相關。本研究除了瞭解企業社會責任資訊如何影響投資者的投資決策外，更希望能提供企業經營者作為經營策略之參考。 / Abstract The purpose of this study is to investigate the market reaction of positive and negative CSR announcements. The empirical results show that there is a significant positive (negative) relationship between positive (negative) CSR announcements and abnormal stock returns. Furthermore, this study establish a regression, trying to find whether company size, business industry, type of negative CSR announcements will have a relationship with negative CSR announcement’s abnormal returns. The author of this research hopes that the findings in this study can not only understand how CSR announcements effect the investors but also help managers develop a CSR strategy.