Abstract: Because of the environmental protection rules in the WTO agreements,nonstandard environmental criteria in the world as well as the disadvantageous position of the developing countries in international trade,such rules,in fact,did not reach the expectations of Environmental Non-governmental Organizations（NGOS).Therefore,the NGOS turned to participate in the WTO dispute settlement procedure as amicus curiae.In the three famous judicial cases,namely “United States-Import Prohibition of Certain Shrimp and Shrimp Products”,“European Communities-measures affecting asbestos and products containing asbestos” and “ Brazil-Measures Affecting Imports of Retreaded Tyres”,WTO dispute settlement body gradually accepted amicus curiae briefs submitted by Environmental NGOS.In order to achieve the purpose of WTO concerning sustainable development,to improve the judicial transparency in environmental trade disputes,to solve cases fairly and to make the international community pay more attention to environmental issues,WTO dispute settlement body should not only take amicus curiae briefs into consideration in its practice,but also formulate the rules on amicus curiae briefs in the light of substantive rules and judicial practice of WTO.

Key words: environmental NGOS, amicus curiae, trade liberalization, environmental protection, WTO