Trade in service, which deals with intangible product, is distinguished from trade of goods for tangible product. The current multilateral service trade is based on GATS which includes MFN, securing the predictability as well as transparency of related service rules, specific commitment basis market access national treatment. Recently the WTO service disputes are increasing according to the frequent filing complaints against the regulation of service trade in China. The rules of GATS are not as strict as those of GATT. The commitment schedules, which were materialized between members, gets binding effect through the obligatory provisions of GATS. The GATS is inseparable relation with the Appendix of finance, of telecommunication, and of air transport, with the schedules of commitment of member states, and with the reference paper to the 4th protocol. GATS article XIV which is the general exception of GATS has a similar structure of GATT article XX. Based on the possibility of filing to the WTO, there is a need to examine whether the whole rules, regulation, and policy international trade in service of Korea perfectly macthed with the GATS. Korea with poor resources should take up the more positive attitude for the opening of international service market. According to the reciprocal aspects of concession, if Korea doesn't open a service market, the other WTO member country wouldn't allow Korea to access the their market as well as national treatment.