本文採用一階段隨機邊界分析法（Battese and Coelli, 1995）衡量2004 年第一季至2008 年第三季台灣上市櫃證券商的技術效率，並將Orea（2002）提出的產出導向一般化Malmquist生產力指數改寫成投入導向模式，用來分析台灣上市櫃證券商的生產力變動情形。實證結果顯示，小型券商之經營效率平均而言比大型券商之經營效率高，而大部分的證券商都呈現規模報酬遞增的技術狀態，可見台灣上市櫃證券商整體而言規模不夠大，必須設法再擴大至適當的規模方可發揮規模經濟效果。另外，較多的股本雖然理論上具備較強的競爭優勢，但可能沒有適當的決策支持，造成資源浪費反而降低經營效率；股價指數愈高，在相同的投入之下有較多的產出表現且較有能力調整規模至規模報酬較佳的狀況，因而提高經營效率。 / This paper adopts one-stage stochastic frontier analysis (Battese and Coelli, 1995) to measure technical efficiency of listed securities firms in Taiwan from the first quarter of 2004 to the third quarter of 2008. In addition, inspired by the Orea (2002) output orientated productivity model, this paper derives an input orientated generalized Malmquist productivity index to analyze the productivity change of the firms. The empirical results reveal that smaller securities firms are more efficient than larger securities firms in average. The majority of securities firms are operating with increasing returns to scale, indicating that the scale of listed securities firms in Taiwan are generally not large enough, so firms need to enlarge their scale in order to get the effect of economies of scale. Although more capital stocks possess stronger competitive advantage theoretically, without proper strategy to support the firms may waste resources and result in operational inefficiency. Operational efficiency is positively correlated with stock index.