關鍵字:智利、阿根廷、外交政策、國家利益、馬爾維納斯群島 This paper is based on the international relations theory- Realism, Neo-liberalism, Social constructivism and Geo-political code under different historical background as the theoretical structure to explore the formulation of Chile’s foreign policy towards Argentina over the Malvinas/Falklands Islands dispute of sovereignty in order to analyze more comprehensively how Chile ajusts their foreign policy according to the change of preference and definitions of their national interests. The Security Dilemma and Military Imbalance in South America made Chile join the clandestine Anglo-Chilean Alliance against Argentina during the Malvinas War in 1982. It shows that in the atmosphere of the Cold War, "national security" undoubtedly was the supreme national interests. However, since the "re-democratization" of both Chilean and Argentine governments, the restart dialogue and mutual understanding established not only in dispute settlement mechanism but consensus on reciprocal cooperation to promote diversive development and bilateral integration under the concept of "international regime". 2014 is the 30th anniversary of the “Peace and Friendship Treaty between Chile and Argentina”. Also the “Treaty of Maipú for Integration and Cooperation” has strengthened the current relationship between Chile and Argentina. The two heads of state acknowledge the need to make joint effort for the regional integration of South America. As regards to the Malvinas Islands sovereignty dispute, Chile adopts his advantage of "niche diplomacy" as a mediator between Argentina and U.K.; meanwhile, Chile hosted the naval exercises with Brazil and U.K. Chile is performing co-competitive position towards Argentina in this field. Nonetheless, the two-track foreign policy served Chile’s best interests to enhance his national image as a "pacifist", to win political identification from South American countries and to protect his traditional interests in both Pacific and Atlantic Oceans and Antarctica.