對於公司資本結構的實證研究，傳統文獻的研究樣本未納入金融產業。Kuo與Lee（2003）對商業銀行資本結構決定因素的分析，是公司資本結構研究上的新嘗試。本文則針對臺灣的證券業進行業內比較分析，以討論部份財務理論模型，尤其是Titman（1984）關於產品特性與資本結構互動關係的理論。本文使用固定影響追蹤資料迴歸模型分析，發現地方性的小證券公司與上櫃的大證券公司，獲利能力相當。若從股東權益的每股盈餘方向作考量，則後者顯著大於前者，後者的業務項目也趨於多元化，而非集中於證券經紀業務。前者的公司負債比率顯著低於後者。經由本文進一步分析的結果，本文建議：證券公司如欲擴大規模或擴展業務範圍，則需伴隨舉債能力的提昇。

Traditionally, empirical studies on corporate capital structure exclude financial firms from the target sample. Kuo and Lee (2003) is one of the few attempts to conduct empirical analysis of determinants of financial industry. They analyze the capital structure of commercial banks in Taiwan. In this paper, I try to analyze the capital structure of Taiwan's security industry and discuss related financial theory, especially Titman's (1984) theory on the interaction between product attributes and capital structure. I will use a fixed-effect panel data regression model to find that an OTC firm's profitability is about the same as a small firm's Yet, an OTC firm's EPS is significantly larger than a small firm's. An OTC firm's service is much more diversified and does not rely on brokerage only. An OTC firm's debt ratio is significantly higher than a non-OTC firm's. This research suggests that to compete with foreign security firms in the event that Taiwan becomes a member of the WTO, Taiwan's security firms must strengthen their ability to raise debts.