本論文以國內2001-2005年之上市櫃公司為研究對象，針對其轉投資層數與股權結構型態進行台灣集團企業股權結構複雜度與企業經營關聯性之研究。有別於集團企業之實證研究，一般均以比較集團與單一企業經營績效與公司價值，來間接推論集團化相關理論之合理性。本論文嘗試直接從形成集團企業之經濟因素著手，探討股權結構複雜度對於企業交易成本、融資成本與決策控制力等經營層面之影響，以期能更深入瞭解集團企業之成本與效益。實證結果顯示，集團企業股權結構複雜度之效益無法反映於較低之交易成本，但可反映於較低之融資利息成本。本論文之實證發現，集團企業形成複雜股權結構主要係基於財務而非營運之考量。最後在決策控制力方面，分析結果顯示，複雜股權結構與股份控制權有顯著的正向關係，為「東亞國家之最終控制者，傾向於透過金字塔結構或交叉持股，以較低現金流量極大化控制權」之說法，提供實證證據。 / We explore the relationship between the complexity of a business group’s ownership structure and operation by using a sample of Taiwanese companies listed in Taiwan Stock Exchange and Over the Counter during 2001-2005. Instead of using Tobin’s q or ROA, we begin with the economic background of business group directly and discuss how the complexity of ownership structure influences the benefits and costs of business operation, such as operation cost, financing cost and ultimate control. Our empirical analysis indicates that the influence of complexity of ownership structure in operation cost is uncertain. According to related research in Taiwan, the main purpose of complexity of ownership structure is not for operation but for financing or restrictions of laws. This may be result in the insignificant effect on operating cost. Second, we find a positive and significant effect on financing cost. This result also supports the arguments about the purpose of complexity of ownership structure. Finally, our analysis offers empirical evidences that control is typically enhanced by pyramid structures and cross-holdings among firms in East Asian countries.