With increment of quantity of inspection and concerns on plant quarantine, plant quarantine faces big challenges internationally as well as domestically. The fast changing environment surrounding plant quarantine makes the role of international quarantine cooperation more important. The m떠 or roles of international cooperation in NPQS are bilateral negotiation to facilitate export of Korean agricultural products, augmentation of contributions in multilateral cooperation, scientific and reasonable progress on import requirement from exporting countries and timely collection and taking measures on international information related to plant quarantine. The major international organizations of plant quarantine are WTOjSPS and IPPCjFAO. WTOjSPS and IPPC expedite development of international standards and guidelines for implementation of scientific and transparent phytosanitary measures. NPQS holds bilateral meetings with various trading partners. Through the bilateral communication, quarantine issues on export of Korean agricultural products, import quarantine requirements of foreign agricultural products and other bilateral issues are discussed. With faithful conduct of the roles of international cooperation as importance part of plant quarantine, plant quarantine can contribute to prevent introduction and spread of exotic pest not only into Korea but also to our trading partner countries which lead to protection of agricultural and natural environment.