The purpose of this study is to understand the architectural space of Seungjeongwon (承政院), the Royal Secretariat, in the early years of Joseon Dynasty. The Royal palace can be divided into three parts, political space, living space for king and his family and offices for government official in the palace. So first, we should to understand the characteristics of each space in the Royal Palace. The result of this study is following. Seungjeongwon of the Joseon Dynasty was where Seungji (承旨), Juseo (注書), Sagwan (史官), Seungjeonsaeg (承傳色), Seori (書吏) and Harye (下隷) worked together. The architectural space of Seungjeongwon was separated into Jeongwon-Cheong (政院廳) and Juseo-Cheong (注書廳). Jeongwon-Cheong was the office for Seungji, where Sagwan worked as well as Seungji and Juseo. The form of Jeongwon-Cheong (政院廳) in Kyung-bok Palace was similar to that depicted in Eundaegyecheop (銀臺契帖), which was painted the meeting of Seungjis. Juseo-Cheong was the office for Juseo and Sagwan and there was a break room. Apart from Jeongwon-Cheong there were rooms where Seungji could work or take a rest. As with the office of Seungji, the space for Juseo also had rooms for Juseo. There were also rooms for Seori and Abang (兒房) which were rooms for servants.