The object of this paper is to provide an analysis of the way in which MFN has been interpreted and applied in the context of GATT and the WTO agreements. In the first part emphasis is placed on MFN under the GATT Firstly it discusses the inclusion of the MFN principle in the GATT, especially focusing on Article I:1 of the GATT with its exceptions. Secondly, it discusses the relationship between MFN principle and national treatment principle. Thirdly it points out the issues regarding the interpretation on the MFN principle through the analysis of various cases under the WTO. Fourthly it considers the MFN principle located in other covered agreements, such as GATS and TRIPS. Fifthly it discusses the interpretation on GATT Article I:1 though several cases that analyze the requirements of this Article, its exceptions and the core concept of the MFN principle, the determination of like product. In the second part, it discusses the MFN principle under GATS and TRIPS, as it still serves as a core concept in both agreements. In the last part, it provides an assessment of MFN under WTO jurisprudence, with several issues regarding several regional trade area and plurilateral agreements being raised
