This study is for revealing that functions, status, and character of Saetaek which was one of the Royal Offices were changed. Because numerous researchers have claimed that character of Saetaek is the literary office. Thee conclusions are as following The officers of Saetaek were very low in position as the literary officers in the Samguksagi , and The Saetaek was the office that was responsible for odd jobs of the Royal Court in the the Wooden Documents escavated at Anapji. Therefore, Saetaek was not literary office but the odd jobs office until the early 9 cent. However, Saetaek`s status had been changed by assigning officers that were higher rank then the regulation from the middle 9 cent. By changing the name from Saetaeck to Jungsasung, the officers who had literary ability were assigned after 865th year. They made important national inscriptions as well as the massages of the king. In addition, they became the emissary. As a result of that, the character of Jungsasung was changed the attendant office and the literary office.