The European Union, as the world's largest regional economy, has traditionally been an important trading partner of China. Since the 1980s, the European economy has been hovering in the doldrums as a result of the combined effects of inflation, reduced investment, rising unemployment and industrial restructuring. In order to protect the unified market, stimulate the economic recovery, the EU frequently use technical barriers to set up trade barriers, and the European uniform standards constitute one of the main content of trade barriers. The study of the European harmonized standards and their development agencies will help us to establish an effective trade early warning mechanism for the EU.

      In order to meet the needs of social and economic development, the EU member states have developed their own national standards, so that products into different countries, increased the cost of adapting to different standards, reducing product competitiveness. In order to establish and maintain the interests of the unified market, in August 1990, the European Commission issued the "Green Paper on the Development of European Standardization", said to be in the European level to develop human health. Personal safety, environmental protection and consumer interests of the European standards (EN), to harmonize the national standards of member countries. The European Union requires that, after the official release of each European standard, Member States must, within six months, adopt national standards for their contents and structure without any changes and revoke national standards that are in conflict with this standard.

In the process of developing European standards, the form of harmonized document (HD) should be used when the national bias of Member States can not be avoided. Each harmonized document must be used at the national level: either by national standard or by publicizing the number and title of the harmonized document. However, regardless of which of the two approaches, Member States must revoke the original criteria that are in conflict with this coordination document.

      In addition to the above two forms, temporary standards (ENV) can be developed in areas where technology is rapidly developing or urgently required. Member States should also adopt provisional standards for national standards, but before the interim criteria are translated into formal standards, Member States may temporarily retain the criteria against them without having to be revoked.
     
      At present, the European uniform standards in the EU member states national standard in the proportion has been as high as 80%. At the same time, the European harmonization standards, while increasing the degree of intra-EU trade liberalization, but for countries outside the region, is clearly expanded the scope of technical barriers to trade.

      Uniform European standards do not fall within the scope of legislation. In accordance with the formal approval of the EU Directive 83/189 / EEC, the development of the European harmonized standards is mainly carried out by the European Committee for Standardization (CEN), the European Committee for Standardization (CENELEC) and the European Telecommunications Standards Institute (ETSI).