由於購併已成為現今為企業提高市佔率的一項重要手段，我國在2002年通過「企業併購法」後為企業提供了這方面的機會，其中又以上市櫃電子業公司的宣告最多，購併對象包括國內與國際的目標公司。另一方面，隨著「企業併購法」而衍生的「企業分割簡易上市」之規範，使企業專注於獲利的事業部門。至於國內與國際購併以及購併與分割宣告效果是否存在不同的程度則有待進一步之探究與比較，此即本研究之目的。本研究以2002年至2012年臺灣上市櫃電子公司為研究對象，透過事件研究法進行日資料之分析。研究結果有以下四項發現，第一，整體電子業之購併宣告並沒有顯著宣告效果；其次，雖然國內與國際購併無顯著宣告效果之差異，但結果顯示，國際購併宣告似乎有資訊外洩之情形。第三，分割宣告產生負向異常報酬的結果。最後，購併宣告的異常報酬顯著大於分割宣告之結果。

As merger and acquisition (M&A) provides the means of increasing marker shares for firms, the Business Mergers and Acquisitions Laws (BMALs) in 2002 allowed Taiwan companies to conduct M&A activities. In fact, the number of announcements is accounted mostly from the listed and OTC electronic firms and includes international and domestic ones. On the other hand, the spin-off regulations in 2002 gave firms to focus profitable businesses. As a result, the difference of announcement effects between domestic and international M&A and the one between M&A and spin-off need to be further investigated. The sample of daily stock returns is collected from listed and OTC firms during 2002-2012 under the event study. The findings are as follows. First, there is no significant M&A announcement effect as a whole. Second, although there is no significant abnormal return difference between domestic and international M&A, it seems that the information leakage occurs in the international case. Third, the spin-off announcement results in negative abnormal returns. Finally, the abnormal returns from M&A announcements are larger than those from spin-off announcements.