The study proposed the mediation institutionalization in arbitration procedure of commercial dispute like followings: First, the foundation of mediation provisions on arbitration law and the maintenance of mediation regulations on arbitration rules have to be preceded before all. Second, arbitration board has to decide whether to progress or not before starting arbitration. Then, they must clearly notify the party about the mediation procedure, the confidential agreement, and the independence of mediation. Third, if decided to accept the mediation procedure, arbitration board has to select appropriate mediator after consult with the party in 30 days. Fifth, the arbitral tribunal can submit a written application for mediation after starting the mediation procedure and reach a verdict if two parties make an agreement. Fourth, the information getting from the mediation procedure has to be maintained confidentiality. Finally, Mediation procedure can be closed regardless whether the arbitration is reached or not.