本研究主要是建立一隨機邊界成本與無效率模型，分析台灣有線電視產業並利用其估計結果衡量台灣有線電視產業是否有規模經濟、密度經濟與是否達到最適規模並比較其效率。 根據Battese and Coelli (1995)之模型，估計目前61 家有線電視系統商，在2001-2003 年之縱橫資料。研究發現，台灣有線電視產業並未有享有規模經濟而是存在密度經濟，在成本效率之比較上，多系統經營商(MSO)比獨立系統商更有效率且有線電視產業存在技術進步之現象，最後利用估計結果可以求出台灣有線電視之最適家數為22 家，每一家廠商之最適收視戶數約為18 萬戶。 The principal aim of this paper is to estimate a stochastic frontier cost function and an inefficiency model of the cable television industries in Taiwan .Furthermore,using the results to analyze the cost structure in order to assess economies of scale and density .Eventually, defining the optimal size of the firms and comparing their efficiency with those firms. For this purpose, we use the methodology proposed by Battese and Coelli(1995), based on panel data of 61 cable television firms operating over the period 2001-2003. The results reveal that the scale economies do not exist but exhibit the density economies in Taiwan’s cable television industries. Secondly, we find that the MSO firms are more efficient than the independent firms and all of them show the advancement of technology. Finally, based on the estimation of a stochastic cost frontier, we find that optimal scale of Taiwan’s cable industries should be accommodated to 22 firms and on average, the service of one firm is approximately 186,660 subscribers.