The paper analyzes the role of "institutionalization" in preserving and building peace in the disputed East Sea. From 2009 till now, such institutions as the Declaration on the Conduct of Parties in the East Sea (DOC) and the United Nations Convention on the Law of the Sea 1982 (UNCLOS) are facing constraints and failure in defining the act among parties. In an attempt to seek peace and common prosperity, a "new order" should be reestablished in which the urgent needs of the "institutionalization" process as a radical and durable solution must be emphasized in order to find unanimity between the parties concerned. However, the speed of "institutionalization" will certainly depend on the policy of the main agents on the East Sea, including the ASEAN countries, China and the United States. Their positions, conditions and strengths are different, with various impact factors, which makes the choice of the parties quite different. Although "institutionalization" can be the best solution for parties to resolve the issue peacefully and to minimize risks, each party has its own calculation and target. The attitude of these countries depends primarily on the balance of power between major powers and the relationship between the choices of each one.