現金增資是台灣資本市場主要的籌資方式之一。現金增資用於資本支出對公司長期經營績效的影響，一直是利害相關人士關注的焦點。本研究以1997年至2008年在台灣股票上市上櫃公司720家現金增資的公司為研究對象。本研究利用複迴歸模型，以現金增資用途為自變數、公司治理機制為干擾變數(含董監事規模、董事長兼任總經理、十大股東持股比率、董監事持股比率、經理人持股比率、法人機構持股比率、四大會計事務所簽證)，公司長期經營績效變化為應變數，探討現金增資用途、公司治理機制與長期經營績效的關係。 本研究實證發現公司辦理現金增資後的長期經營績效普遍下滑，現金增資用途對公司長期經營績效有顯著負向影響。董監事規模、董事長兼任總經理、十大股東持股比率、經理人持股比率、四大會計事務所簽證皆無顯著干擾現金增資用途對公司長期經營績效的影響。然而，董監事持股比率、法人機構持股比率則干擾現金增資用途對公司長期經營績效有負向影響。董監事持股比率與法人機構持股比率能發揮公司治理效能，扮演重要的干擾角色，減少現金增資用途對公司長期經營績效的影響，本研究結果可做為利害相關人士的參考依據。 Seasoned equity offerings (SEO) is one of the major options to raise capital for Taiwan corporations. The effect of capital expenditure of SEO on long-term operating performance is always the focus of stakeholders. This study uses multiple regression analysis to analyze the relationship between the use of SEO, corporate governance mechanism, and the long-term operating performance. The use of SEO is the independent variable in the empirical model. The mechanism of corporate governance is the moderate variable which includes board size, chairman also serving as CEO, block shareholding ratio, directors of board and supervisor shareholding ratio, managers shareholding ratio, investment institution shareholding ratio and certification of top four accounting agencies. The results show that the SEO firms decrease in long-term operating performance, and the use of SEO significantly deteriorates the long-term operating performance. The effect of the use of SEO on long-term operating performance is not influenced by the board size, chairman also serving as CEO, block shareholding ratio, manager shareholding ratio, or the certification of top four accounting agencies. However, the effect of the use of SEO on long-term operating performance is negatively influenced by the director shareholding ratio and the investment institution shareholding ratio. It shows that the director shareholding ratio and the investment institution shareholding ratio can play a moderate role in the corporate governance, and provides the effectiveness of corporate governance and lessen the effect of the use of SEO on long-term operating performance. The results of this study may provide references for the stakeholders of the companies.