On The Law Of The Wto Dispute Settlement Mechanism Applicable

International courts and tribunals are all faced with the choice of applicable laws when they try cases. Some constitutional instruments of international courts and tribunals stipulate the applicable laws explicitly, for example, article 38 of the Statute of the International Court of Justice, article 21 of Statute of the International Criminal Court. However, DSU doesn't provide the applicable law for the Dispute Settlement Mechanism (hereinafter the "DSM"). It's not very clear that what can be the applicable laws for the DSM.The Panel, the Appellate Body and the Arbitrators are subjects who apply laws in the DSM. The Dispute Settlement Body, the sectetariat, the Drector-General and the Expert Review Groups, though taking part in the settlement of the disputes, don't apply laws. Issues in disputes settlement can be classified into substancial issues and procedural issues, which are different from each other in application of law. Legal interpretation is distinct from the application of law, and they play different roles in the legal process of the DSM. The distinction of the two is critical for us to recognize what are the applicable laws in the DSM correctly.The covered agreements in Appendix 1 to the DSU are the main sources of law that the DSM applies. Generally speaking, Trade Policy Review Mechanism, declarations and decisions of the Ministerial Conference and agreements which are not stipulated in Appendix 1 to the DSU can't be applied by the DSM. Some non-WTO treaties become incorporative treaties because the provisions of some WTO agreements. The application of incorporative treaties should be recognized as the application of WTO agreements. The DSM applies different agreements on the same measures of a contracting party under certain circumstances.Non-WTO laws play different parts in the legal process of the DSM according to their status. Concretely speaking, non-WTO treaties can't be applicable laws when the DSM settles the disputes, yet they can be invoked as the sources of law for legal interpretation by the DSM. The adopted Panel Reports and the Appellate Body Reports, judicial decisions of other international courts and tribunals, teachings of publicists can only be reference for legal interpretation during the legal process of the DSM. Domestic laws of contracting parties are usually raised as factual issues in disputes settlement. Customary international law and the general principles of law can be applied to the facts of the disputes by the DSM.The DSM should limit its power when applying laws in disputes settlement. The Panels and the Appellate Body shall not nullify or impair benefits accruing to any Member under WTO agreements, nor impede the attainment of any objective of those agreements. The DSU should stipulate the applicable law of DSM definitely.