Globalization has made exchanges between countries easier and tighter in all areas, including international economy and human exchanges. ASEAN was formed for the economic cooperation of the ten Southeast Asian countries sand for peace in the Southeast Asian region. ASEAN countries are receiving much attention in the era of globalization with high economic growth, economic potential and a large percentage of young generation. South Korea has also sought to move away from the four major powers(U.S. Russia, China, Japan) and advance to Southeast Asia to expand its diplomatic and economic horizons. Moon Jae-in administration inaugurated in 2017 high economic potentials of the ASEAN countries interested in foreign policy. This thesis aims to identify the analysis of South Korea’s New Southern Policy and influences and impacts on South Korea and ASEAN countries. In particular it describes the background and causes of the establishment, definition, policies and goals of South Korea’s New Southern Policy, and also describes the South Korea-ASEAN relations caused by the New Southern Policy. This paper used the qualitative approach as its research method to answer research questions. This research used the neoliberalism theory as the main theory to explain the establishment background of the New Southern Policy and the policy implementation. Regionalism, globalization, and foreign policy theory helped to explain neoliberalism theory and New Southern Policy. New Southern Policy, which is based on 3PS(People, Prosperity, Peace), has established and implemented 16 policies related to increase human exchanges, economic cooperation and security cooperation between South Korea and ASEAN countries. New Southern Policy is steadily pushing for various policies to promote win-win prosperity between Korea and ASEAN and expand diplomatic horizons, and aims to make a policy sustainable as President Moon administration’s new foreign policy. And the NSP is started with five of ASEAN countries with are Malaysia, Indonesia, Singapore, Brunei, and Vietnam. Therefore, this research would be highlighting the policies that promoting now and achievements of New Southern Policy to South Korea and ASEAN countries.