Recently, there has been in various communities and localities in Korea a series of experiments of functioning community/local currencies (CCs/LCs), which are normally used only in a bounded territory like towns or localities, as a kind of complimentary currencies. People believe CCs/LCs enhance residents’ purchasing capacity and cause local multiplier effects by encouraging transactions and money flows inside local areas. This study deals with such effects throughout System Dynamics modeling and quantitative simulation, focusing on the case of Poomasi in Gwacheon city. The result implies an introduction of CCs/LCs contributes to an increase of residents’ income and local transaction, especially when the running systems of CCs/LCs are based on community spirits and senses.