Official Interpreters(譯官) were important players in foreign trade and diplomacy in Goryeo dynasty. Especially during the period of Yuan’s intervention in Goryeo affairs, the official interpreters became more important and they were promoted to high official ranks. In early Goryeo, the Haneodogam taught Chinese and the Yeokeodogam taught Nuchen(Jurchen) and Khitan languages to train official interpreters. During the period of Yuan’s intervention, the Goryeo government established the Tongmungwan which taught Chinese used by the Yuan Mongolians and new Mongolian letters to train young official interpreters of under 40 years old. As some official interpreters were promoted to a higher rank and became the secretaries close to the kings, some administrators became interested in the official interpreters career. Appointment of the administrators as official interpreters raised the political and social status of the official interpreters. During the period of Yuan’s intervention, official interpreters had different attitudes in their career development. While some official interpreters such as Gang Yunso pursued their career by flattering Yuan emperors and pro-emperor groups such as Hongdagu under the reign of Wonjong, Jo Inkyu and other official interpreters sided with the Goryeo king and established their positions under the reign of Chungyolwang. During the period of Chungseonwang and Chungsukwang, the official interpreters such as Yu Cheongsin had to choose his political position between Shenwang(審王) and the kings of Goryeo. In late Goryeo, an official interpreter was a career to move up to high positions in the court with his own ability and labor regardless of his social status. They contributed to the development of the society to some extent. As Yuan and Goryeo exchanged extensively and actively, more kings and administrators became fluent in Mongolian language and official interpreters could not enjoy such high positions any more. Especially as the power struggle for kingships between Shenwang and Goryeo king developed during the period of Chungsukwang, official interpreters were forced to make political decisions with whom to take side for their own interests. During the transitional period from Yuan to Ming dynasty, official interpreters focused on their professional duties. Seol Jangsu, one of the interpreters at the time, became a successful interpreter but rather as an administrator who passed the official state career examination. In summary, though the official interpreter career was an open career path to the royal court among commoners, it had a certain limit. In general, the offsprings of successful official interpreters pursued their career through the state examinations or the Emseo system, a family spoils systems for court positions. The goal of the official interpreters was to move up to high positions in the administrative ladder lacking professional pride in their job duties.