一、最惠国待遇原则
最惠国待遇原则是国际经贸关系中一项古老的原则。GATT1947第1条第1款首次在多边贸易体制中引入了最惠国待遇原则，但其仅仅适用于货物贸易。GATS作为第一个多边服务贸易协定，同样也规定了最惠国待遇原则。GATS第2条第1款规定：“关于本协定所涵盖的任何措施，每一成员对于任何其他成员的服务和服务提供者，应立即和无条件地给予不低于其给予任何其他国家同类服务和服务提供者的待遇。”这一规定构成了GATS的核心条款。
Article Ⅱ
Most-Favored-Nation Treatment
1.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 favorable than that it accords to like services and service suppliers of any other country.
2.A Member may maintain a measure inconsistent with paragraph 1 provided that such a measure is listed in, and meets the conditions of, the Annex on Article II Exemptions.
3.The provisions of this Agreement shall not be so construed as to prevent any Member from conferring or according advantages to adjacent countries in order to facilitate exchanges limited to contiguous frontier zones of services that are both locally produced and consumed.
（一）GATS最惠国待遇原则与GATT最惠国待遇原则的区别
GATS中的最惠国待遇原则与货物贸易领域中的最惠国待遇原则有着密切的联系，这一点从两者的措辞就可见一斑。但是，由于货物贸易与服务贸易本身所存在的差别，GATS与GATT在最惠国待遇原则的适用上不可避免地会出现一些差异。
第一，The Most-Favoured-Nation Treatment in the GATS applies not only to the service, but the service provider; The Most-Favoured-Nation Treatment in the GATT only applies to the product itself. 这是由服务贸易中服务与服务提供者不可分离的客观现状决定的。