This study has two purposes: the first, to analyze limitations in local government’s implementation of public diplomacy, based on the concept of new public diplomacy theory with the case of Daejeon metropolitan city, the second, to advance the policy proposals. This study, based on this, analyzes legal and institutional foundation and management foundation in the light of the results of Daejeon city’s implementation of the project perceived as public diplomacy. This study concludes that the weakness of those foundations, the conflicts between local government and central government, and restrictions in local government activities as a key public diplomacy actor have been existed. This study also criticizes the fallacy of management of human infrastructure. This conclusion shows that Daejeon city’s misperception and misunderstanding of public diplomacy is the first cause which produced those results and is to pave the hermeneutical possibility to criticize Deajeon city’s real intention to pursue the interest of political power, that is the preservation and the expansion of political power of the elected political elites. Therefore this study suggest as policy proposal the re-establishment of the paradigm for public diplomacy, based on the concrete and acurate re-recognization of the conception of public diplomacy, the improvement of institutional management manual, the objective and continuous evaluation of policy for public diplomacy.