The arbitration rules regulate the procedures carried out by the parties and arbitration institutions and tribunals. The parties may agree on the applied rules. Such arbitration rules could be made either by the arbitration institutions or by the international economic and trade organizations. The arbitration rules are contractual in nature, because they could be applied only at the parties’ consent. While choosing the applied arbitration rules, the parties could make some amendments subject to law. The national arbitration law always applies to the arbitration carried out in its territory. Such application needs no parties’ choice. Moreover, the national arbitration law also serves as important supplements to the arbitration rules. If the parties or the arbitration rules failed to provide the matters to be arbitrated, or provided such matters unclearly, the parties or arbitral tribunal may turn to the applied arbitration law. The different nature between the arbitration rules and law leads to the different scope of application and legal binding force.