This paper discusses the meaning and nature of the six Principles of the TBT Committee Decision on International Standards and examines the tendency to oblige the Principles outside the WTO rules. After the Uruguay Round, international standards have melted into various WTO agreements. However, TBT Agreement, the most basic agreement on international standards among WTO agreements, does not have an exact definition of international standards, and WTO members' dispute over how to define and interpret them has still been at the center of debate. In particular, the U.S. and Japan argued that there are still many ambiguities in interpretation because the international standards of the TBT Agreement do not reflect technology and market relevancies, and the definition of the international standard is not defined in the TBT Agreement. Developing countries also have argued that international standardizing bodies should consider the position of developing countries that cannot participate in the process of developing international standards. In these circumstances, ‘TBT Committee Decision on International Standards’ appeared in 2nd Triennial Review of the Operation and Implementation of the TBT Agreement, reflecting each country’s position on international standards. In the course of the 1st Triennial Review in 1997, countries began to discuss their views on what the international standard should be like, and in the 2nd Triennial Review in 2000, ‘TBT Committee Decision on International Standards’ set out six Principles that should be considered essential for the elaboration of international standards. Transparency, openness, impartiality and consensus, effectiveness and relevance, coherence, and development dimensions of developing countries are the principles necessary for the development of international standards. However, the mechanism by which the ‘TBT Committee Decision on International Standards' can be implemented within WTO is not plausible, and therefore countries that want to recognize international standards which were created under the principles of ‘TBT Committee Decision on International Standards' seek to find other ways through FTAs. In particular, the United States regards the principles of ‘TBT Committee Decision on International Standards' as a ‘prerequisite' in determining international standards. EU views the principles of ‘TBT Committee Decision on International Standards' as the ‘reason for breaking presumption'. In line with these directions, Korea should also determine how to deal with ‘TBT Committee Decision on International Standards' within the FTAs.