The case of the European Union shows that regional integration can make significant contributions to peace and prosperity; however, where regional integration in Northeast Asia is concerned the dominant opinions are more skeptical. The main obstacle to regional integration is that the initiative has been limited to intergovernmental agreements. This paper contends that a community-building project at the slate level will be likely to gain momentum if multiple levels of regional cooperation are emphasized at the local level. I have selected South Korea and China for this case study, with particular reference to Gyeonggi Province (do) and Shandong Province (sheng), due to their intensive inter-regional exchanges. The examination of various interactions observed at the trans-regional level provides a perspective on the roles of local governments and leads to an invaluable rediscovery of the merits of a bottom-up approach.