The creation of RMU is a good way to coordinate policies and assure exchange rate stability in East Asia. This study conducts research on the RMU`s official role for transactions from theoretical and empirical perspectives. Once the creation of the RMU is agreed, the RMU can be used as an official instrument to monitor exchange rates of Asian currencies between themselves and against the US dollar or the euro, and also can be used as a settlement currency for official transactions. Drawing a parallel with the ECU, this paper suggests the establishment of an Asian exchange rate system like the European exchange rate system, and the creation of the Asian Exchange Stabilization Fund to facilitate a monetary union in Asia. The RMU can be developed into a parallel currency as well. In this regard, we suggest that the long-term vision of a monetary union in East Asia is essential and this should be presented in the form of a common declaration.