在企業聚焦核心事業以及修正多角化策略的浪潮下，企業分割已成為近來企業進行經營績效以及組織重整的重要工具。因此，本研究以國內上市公司為樣本，以西元2002年至2007年12月底為研究期間，探討上市(櫃)公司分割後，其母公司長期投資績效與長期營運績效。研究結果顯示在分割後股票通常存有正向累積異常報酬。而企業的分割活動通常可以改善公司獲利能力與償債能力。本研究主要發現如下，針對公司分割進行探討，企業進行分割活動，長期營運績效分析結果顯示獲利能力逐年上升，且高於同業。分割後公司營運績效之資產使用周轉率會降低，其餘獲利能力與償債能力好轉，但仍不具統計上之顯著性。最後，結果顯示台灣上市(櫃)公司進行分割活動後之投資效益，並未出現顯著之變化。 The wave of enterprises focus on core business and the amendments to the diversification strategy, spin-offs has become an important tool for business performance and organizational restructuring for recent enterprises. In this study, the purpose is to discuss samples of domestic listed companies during the period of the year 2002 to the end of December 2007, the long-term investment and operating performance of its parent company after the segmentation of the listed companies. The results show that the segmentation activities usually accompany with a positive cumulative abnormal returns on its stocks. It can also improve the profitability and solvency for these domestic listed companies. The major findings of this study are as follows. First, long-term operating performance analysis showed that profitability increased year by year and higher than its peers after the segmentation activities. Second, the operating performance of the asset turnover ratios will be reduced but the profitability and solvency will be improved after the segmentation. However, it is still not with statistical significance. Last but not least, the results show that the investment returns of these domestic listed companies did not emerge significant changes after the segmentation activity.