一、最惠国待遇原则的含义以及特征
最惠国待遇（Most Favored Nation Treatment，MFN）是世界贸易组织多边贸易制度中最重要的基本原则和义务，是多边贸易制度的基石。世界贸易组织法律制度之所以成为多边贸易制度，最重要的依据就是其最惠国待遇。根据世界贸易组织的规定，对最惠国待遇原则的修改，必须经全体成员同意才有效。世界贸易组织的《关税与贸易总协定》第1条、《服务贸易总协定》第2条第1款和《与贸易有关的知识产权协定》第4条中，都有关于最惠国待遇的基本规定。在不同的协议中，最惠国待遇义务的含义并不完全相同，各有其严格的适用条件和范围。
（一）最惠国待遇原则的含义
最惠国待遇指一成员方将在货物贸易、服务贸易和知识产权领域给予任何其他国家或地区（无论是否是世界贸易组织成员）的优惠待遇，应立即和无条件地给予其他各成员方。
在货物贸易领域，依《关税与贸易总协定》第1条第1款规定：With respect to customs duties and charges of any kind imposed on or in connection with importation or exportation or imposed on the international transfer of payments for imports or exports, and with respect to the method of levying such duties and charges, and with respect to all rules and formalities in connection with importation and exportation, and with respect to all matters referred to in paragraphs 2 and 4 of Article Ⅲ, any advantage, favour, privilege or immunity granted by any contracting party to any product originating in or destined for any other country shall be accorded immediately and unconditionally to the like product originating in or destined for the territories of all other contracting parties.
在服务贸易领域，《服务贸易总协定》第2条第1款规定：With respect to any measure covered by this Agreement, each Member shall accord immediately and unconditionally to services and service suppliers of any other Member treatment no less favourable than that it accords to like services and service suppliers of any other country.