出口稅是政府對於出口產品於通關時所徵收的關稅，屬於一種出口限制。由於世界貿易組織（World Trade Organization, WTO）一直以來著重於解決進口關稅造成的貿易障礙，出口稅在 WTO 下尚未有明文規範，開發中國家故將其視為一種合法貿易政策工具。出口稅不僅可增加政府稅收，供應大國使用出口稅亦可引導出口原料內銷，使國內原料價格降低，造成變相補貼國內加工業者之效果，供應大國便可以出口成本較低廉的加工產品；相對地出口原料降低造成原料之國際價格提升，便會影響其他國家加工業者之權益。在進口關稅及數量限制於關稅暨貿易總協定（General Agreement on Tariffs and Trade, GATT）中已有所管制的情況下，進口國家開始憂心出口稅使用擴散、影響更多原料供給，故於杜哈回合之討論及 WTO 爭端解決皆引發相關爭議，惟皆未得到進一步管制出口稅之結果。本文參考杜哈回合提案及雙邊貿易談判下之成果，提出於 WTO 下以關稅減讓談判之規範模式，搭配其他考量因素，作為 WTO 下解決出口稅問題之建議。 / The export tax is the custom duty on the exports. It’s a kind of export restrictions as well. As the World Trade Organization (WTO) has always focused on the trade barriers caused by the import tariffs, the export tax has not yet been clearly defined in the WTO. The developing countries regard it as a legitimate trade policy tool. The export tax can not only increase the government revenue, for major suppliers, the export tax can also guide the exports to be sold domestically, so that it can make the domestic supply increase and the internal price decrease, resulting in a disguised subsidy to the domestic consumers. If the export tax is imposed on the raw materials, major suppliers can export cheaper processing products, getting a better competitive advantage. However, it will also affect the interests of the processing industries in the other countries. Therefore, importing countries begin to worry about the use of export taxes.Through different rounds of discussion and the related dispute settlement under the WTO, the controversy over the export tax have not been further tackled. Based on the related proposal in the Doha round and the related regulations of the bilateral trade agreements, this article would put forward the method of the tariff reduction negotiations under the WTO, with some suggestions to increase the feasibility, to solve the problem on the export tax issues.