隨著數位匯流發展趨勢，愈來愈多的媒體透過購併，延伸市場競爭力至其他平臺，形成大型跨媒體集團。過去討論媒體購併是否造成壟斷時，大多檢視相同水平市場集中度是否過高，或是垂直整合是否對獨立業者形成進入障礙，較少有系統檢驗跨不同平臺間媒體購併的影響。本研究將介紹美國、德國與韓國的跨媒體購併指標與經驗，了解不同加權與計算的優缺點，並透過檢視近年臺灣跨媒體購併案例，討論適合臺灣媒體產業環境下的跨媒體購併指標與應用。

Under the development of digital convergence, more and more mergers and acquisitions are taking place across media industries. In the past few years, most studies on horizontal mergers and acquisitions examine the concentration ratios or on vertical cases concerning entry barriers that block new entrants. Few research papers have discussed the impact of cross-media merger and acquisition and how to calculate the index. Thus, this paper introduces the experiences of index construction and application from the U.S., Germany, and South Korea, in order to provide a better analysis and concentration measurement index across different media for Taiwan.