Mongolia is a huge, landlocked, middle-Asian country bordering Russia in the north, and China in the south. Mongolia was under socialism from 1921 to 1990, and its political system has started moving toward capitalistic democratism in 1990. The history of the Mongolian Oral & Maxillofacial Surgery can be divided into four periods; the incipient period($1956{sim}1971$), the period of early development($1971{sim}1981$), the period of active development($1981{sim}1991$), and the period of reformation($1991{sim}$). Mongolian Oral & Maxillofacial Surgery had been developed by the cooperation of Soviet Union and Eastern European countries before the 1990s, but the role of Korea, Japan, and western countries has been increasing from the 1990s. In Mongolia Oral & Maxillofacial Surgery is well recognized to the people and is considered as one of the specialized medical field. There are specialized departments of Oral & Maxillofacial Surgery in State Central Hospital, Child & Maternal Research and Clinical Center, and Oncology Center in Ulaanbaatar. Now, the basic knowledge and surgical technique of the Mongolian Oral & Maxillofacial Surgeons are satisfactory. But because of the difficult social and economic situation, there is a shortage of surgical instruments and materials, and acquirement of new knowledge is not easy. In 1998 the Mongolian Association of Oral & Maxillofacial Surgeons was established and its members want to have international relationship to keep up with the new medical information. Mongolia and Korea have ethnic, linguistic and cultural similarity, so the interchange and cooperation between Mongolian and Korean Oral & Maxillofacial Surgeons are recommended to make a beautiful one-world.