6. Fundamental Principles of WTO
6. WTO的基本原则
WTO规则涵盖的领域十分广泛，其规则的复杂程度也相当高，具体规则的理解通常有一定难度。但是，WTO在规则制定和实践中，有一些基本原则是贯穿始终的，如果我们能够很好地理解这些原则，就能更准确地理解和运用WTO的法律规则。但是，对于WTO基本原则应包含内容的概括，可以有不同的标准和方法。
The WTO agreements include about 29 individual legal tests which are normally lengthy and complex, covering everything from agriculture to textiles and clothing, and from goods to services and intellectual property. Added to these are more than 25 additional ministerial declarations, decisions and understandings which spell out further obligations and commitments for WTO members. However, a number of simple and fundamental principles run throughout all of these instruments which, together, made up the multilateral trading system.
Non-discrimination in Trade
For almost fifty years, key provisions of GATT outlawed discrimination among members and between imports and domestically-produced merchandise. According to ArticleⅠ, the famous“most-favored-nation”（MFN）clause, members are bound to grant to the products of other members treatment no less favorable than that accord it to the products of any other country. Thus, no country is to give special trading advantages to another or to discriminate against it; all are on an equal basis and all share the benefits of any moves towards lower trade barriers.
At the second level, once they enter those export markets, the imported goods cannot be treated differently than the same goods produced locally（The second form of non-discrimination known as“national treatment”. ）.
Non-discrimination is an obligation not to discriminate between imported and domestic“like products”and among imported“like products”. If two products are not like products, the non-discrimination principle does not apply as between those products. This raises the important question of what constitutes a like product. WTO decisions examining Article Ⅲ of the GATT 1994 have applied a four part test in which the following factors are examined:physical characteristics（the properties, nature and quality of a product）; HS classification; consumers' tastes and habits（perception and behaviour）, and product end uses.
