Buyongjeong, a pavilion in the Rear Garden of Changdeok Palace, was appointed as Treasure No. 1763 on March 2, 2012, by the South Korea government since it shows significant symmetry and proportion on its unique planar shape, spatial configuration, building decoration, and so forth. However, the designation of Treasure selection was mainly evaluated by concrete science, in that the selection has not clearly articulated how and why Buoungjeong was constructed as a present unique form. Therefore, this study aims to clarify the identity of Buyongjeong at the time of construction by considering its historical, ideological, philosophical background and building intention. Summary are as follows: First, Construction backgrounds and characters of Buyongjeong: Right after the enthronement, King Jeongjo had founded Kyujanggak(奎章閣), and sponsored civil ministers who were elected by the national examination, as a part of political reform. In addition, he established his own political system by respecting "Kaksin(閣臣)", Kyujanggak's officials as much as "Kain(家人)", internal family members. King Jeongjo's aggressive political reform finally enabled King's lieges to visit King's Rear Garden. In the reign of King Jeongjo's 16th year(1792), Naekaksangjohoe(內閣賞釣會) based on "Kaksin" was officially launched and the Rear Garden visitation became a regular meeting. The Rear Garden visitation consisted of "Sanghwajoeoyeon(賞花釣魚宴)" - enjoying flowers and fishing, and activities of "Nanjeongsugye". Afterward, it eventually became a huge national event since high rank government officials participated the event. King Jeongjo shared the cultural activities with government officials together to Buyongjeong as a place to fulfill his royal politics. Second, The geographical location and spatial characteristics of Buyongjeong: On the enthronement of King Jeongjo(1776), he renovated Taeksujae. Above all, aligning and linking Gaeyuwa - Taeksujae - a cicular island - Eosumun - Kyujangkak along with the construction axis is an evidence for King Jeongjo to determine how the current Kyujangkak zone was prepared and designed to fulfill King Jeonjo's political ideals. In 17th year(1793) of the reign of King Jeongjo, Taeksujae, originally a square shaped pavilion, was modified and expanded with ranks to provide a place to get along with the King and officials. The northern part of Buyongjeong, placed on pond, was designed for the King's place and constructed one rank higher than others. Discernment on windows and doors were made with "Ajasal" - a special pattern for the King. The western and eastern parts were for government officials. The center part was prepared for a place where government officials were granted an audience with the King, who was located in the nortern part of Buyongjeong. Government officials from the western and eastern parts of Buyongjeong, could enter the central part of the Buyongjeong from the southern part by detouring the corner of Buyongjeong. After all, Buyongjeong is a specially designed garden building, which was constructed to be a royal palace utilizing its minimal space. Third, Cultural Values of Buyongjeong: The Buyongjeong area exhibits a trait that it had been continuously developed and it had reflected complex King's private garden cultures from King Sejo, Injo, Hyunjong, Sukjong, Jeongjo and so forth. In particular, King Jeongjo had succeded physical, social and imaginary environments established by former kings and invited their government officials for his royal politics. As a central place for his royal politics, King Jeongjo completed Buyongjeong. Therefore, the value of Buyongjeong, as a garden building reflecting permanency of the Joseon Dynasty, can be highly evaluated. In addition, as it reflects Confucianism in the pavilion - represented by distinguishing hierarchical ranks, it is a unique example to exhibit its distinctiveness in a royal garden.