本文研究期間為1996~2002年，研究對象為有進行國際多角化策略的美國企業，資料來源為COMPUSTAT資料庫，研究主題為探討國際多角化、產品多角化以及公司績效之間的關係。
　　研究結果顯示，企業國際化程度與績效表現間呈現倒U型的關係，也就是初期的國際化對企業的績效表現有正向的幫助，但隨著企業國際化的程度增加，過度的國際化程度反而會對企業績效有負向的影響。然而，本研究並未發現產品多角化的程度對於國際多角化與公司績效間的關係有顯著的影響效果。因此本研究進一步將產品多角化區分為相關及非相關產品多角化，結果發現當企業進行相關產品多角化策略時，對於國際多角化與績效間的關係有顯著的正向影響作用；然而當企業進行非相關產品多角化策略時，對於國際多角化與績效間的關係則有顯著的負向影響作用。

　　Theory suggests and previous results show that firm performance is initial positive but eventually levels off and becomes negative as the degree of international diversification increases. Theory also argues that product diversification can positively moderate the relation between international diversification and performance. Therefore, the main object of this research is to investigate whether diversification strategy can really create value for multinational companies. We use the diversification data from COMPUSTAT database during 1996~2002 as sample.

　　The empirical results find that the relationship between international diversification and performance is an inverted U shape, but we could not find signification evidence to support that product diversification can positively moderate the inverted U relation. Moreover, we find that related product diversification could more strongly moderate the relationship between international diversification and performance than unrelated product diversification.

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