本文為瞭解中國證券監督管理委員會於2005年實施股權分置改革後,中國上市公司「一股獨大」衍生的代理問題是否得到舒緩;首先,本研究藉由資本結構理論相關文獻分析,其次歸納出國家持股比例、機構投資人持股比例、內部人持股比例、獨立董事持股比例、董事會規模、董事長兼任總經理等自變數,以及資產報酬率、有形資產、稅盾效果、公司規模、非負債稅盾、成長機會等控制變數,並推論其與代表資本結構的負債權益比率間之關係,建立多元迴歸模型,以探討中國上市公司在股權分置改革實施前後,負債比率與各項資本結構決定因素間關係的變化情形。研究結果主要發現:(1)國家持股比例由股改前不顯著的負向關係轉為顯著正相關,顯示股改後國家仍對上市公司有實質影響力,有助於上市公司取得外部融資,(2)機構投資人持股比例由股改前不顯著的負向關係轉為顯著正相關,支持策略合力假說,(3)內部人持股比例由股改前顯著正相關轉為負相關,支持利益收斂假說,(4)外部董事比例及董事會規模皆轉為顯著負相關,表示中國上市公司公司治理已有改善,較易獲致市場投資人的支持。This study examines the effects of the split share structure reform on the determinants of capital structure of Chinese listed firms. The sample covers the period from 2001 to 2009. The findings indicate that, compared with those before the reform, both the state ownership and institutional ownership are more significantly associated with debt ratio after the reform, however, insider ownership, the proportion of external directors and board size are all more significantly and negatively related to debt ratio. These findings imply that the split share structure reform in China did have effects on the capital structure of Chinese listed firms.