本文以1996至2005年英國2,002個併購樣本,探討不同併購活動與併購標的是否產生相異之股票績效。 我們將併購活動依集中化、多角化、上市、私人或附屬公司標的予以分類,並計算各組宣告併購期間超額報酬及宣告後長期報酬。 不論標的為上市公司或附屬公司,多角化併購宣告報酬均高於從事集中化併購公司1\%,但長期出現反轉的現象。 以私人公司為標的之併購宣告報酬亦高於以上市公司為併購標的者,兩者長期股票報酬則不顯著。 This paper shows in a sample of 2,002 UK M&As between 1996 and 2005 various types and targets of acquisitions have different stock performance. We classify acquisition according to activity focus or diversification, private, public targets and subsidiary and examine the abnormal return to each group as a result of the acquisition announcement and long-run period. The announcement return for acquiring firm shareholder is 1\% higher for diversifying M&As whether the acquired company is public or private even using control variables, but it is reversed over time. Private firm M&As have higher announcement return than public one but long-run abnormal returns of them are insignificant.