近年來，韓國積極發展「中等強權」外交政策，在G20主持多場重要會議，參與發展政策、維和部隊與區域安全議題，韓國並邀請同屬中等強權國家的墨西哥、印尼、土耳其、澳洲，共同成立「MITKA」五國諮商會議。本研究主張：韓國對於自身國家角色概念的認知影響了其外交決策的產出過程，而國家決策者首先對於國家定位有所認識與定義，從而對應其國家角色而制定相關的施政規劃與外交方針。 　　本研究以角色理論作為分析途徑，研究重心聚焦於內部國家特性的成長，以及外部環境如何影響韓國國家角色概念的成形與轉變。本論文特別著重分析韓國與中國的關係，主張韓中雙邊互動逐漸影響韓國對自身角色的認知，並增強了韓國對於提升對中經貿交流與合作的認同，進一步影響了「中等強權」外交政策出台，令這項政策成為身處安全困境並遭受強權環伺的韓國的外交主軸，並促使韓國推廣新興外交政策與成立「MITKA」。 / South Korea has recently focused on developing the middle power diplomacy. It has hosted the G20 global conferences, contributed development assistance, and joined peacekeeping operations. It also promoted “MITKA” with Mexico, Indonesia, Turkey, and Australia. The key factor shaping South Korea’s middle power diplomacy is the identity of national role conceptions. The leaders know the self conceptualization of a country’s role in international politics, then make decision under the influence of national role conceptions. Viewing role theory as analytical tool, this study explores how international and domestic factors affect the course and outcome of ROK decision-making process. The development of Sino-Korean relations shapes the values and identity, makes economic interests continue to effect ROK leaders’s national role conception. Koreans historically consider their country as a victim of great powers , middle power diplomacy may be the key to solving ROK foreign policy dilemmas.