本文旨在檢定高雄港港埠業務是否具有自然獨占以判斷能否藉由開放競爭以提高經濟效率。本文將港埠營運區分為停泊、裝卸與創儲三項業務，以Fourier成本函數建立一個三種投入（勞動、資本與中間要素），三種產出的實證模型並以規模經濟與（或）範疇經濟作為自然獨占之檢驗指標，研究期間為10997-2001年。研究的木顯示1.無論是個別的業務或整體港埠業務均具有顯著性的規模經濟與範疇經濟特性。2.卸裝與倉儲業務有剩餘產能。3.停泊與裝卸兩項業務具有成本互補效果。針對港埠營運具有自然獨占的性質，其產業管理意涵為港坪營運並不能藉由解除管制開放競爭以提高經濟效率，相反的，政府應藉由合乎經濟性的管制措施以減少因市場失靈所產生的福利損失。

This paper examines the natural monopoly of harbor operations. The authors use a multiproduct model which represents harbor outputs with three variables: mooring, stevedoring, and warehousing. A Fourier cost function is used to calculate several cost indicators. The sample covers of monthly data over 1997-2001 period. From the analysis of the cost indicators, it is found that both of individual operation and all of the operations as a whole exhibit significant economies of scale and scope. Moreover, the presences of excess capacity of stevedoring and warehousing have been detected, as well as a presence of cost complement between mooring and stevedoring. Because of a natural monopoly，the operation of harbor outputs cannot improve economic efficient by deregulation and inducting market competition. On the contrary, the government should put more effort into decreasing social welfare loss by economic reasonable regulation.