Naejeon area at Chandeokgung Palace means the areas of Huijeongdang and Daejojeon area. Huijeongdang or Hall of Brilliant Rule is made for the king, and Daejojeon or Hall of Great Creation is made for the queen. These areas were located nearly and repeatedly burned down and rebuilt several times together, but their forms were largely unchanged. However in 1920, they rebuilt in a very different way. The purpose of this study was to estimate construction plans, progress and completion of Naejeon area’s rebuilding. They were reconstructed into eclectic structures as the exteriors were built using basic materials from Gyeongbokgung Palace. So they have traditional-looking appearances, but the interiors consisted of modern equipments and were built by applying foreign style construction techniques. The main floored room of Daejojeon and the area of Huijeongdang were built in standing style by installing radiators and French furnitures. Also, the porch, corridor, storage space and veranda were constructed under the influence of Japanese construction. After the reconstruction, there were changes in the usage of some spaces. Huijeongdang functioned only for Alhyeonso or audience chamber rather than Pyeonjeon or state hall. New organizations created by the Japanese such as Chansi or secretaries office and the Chief secretary’s office were included in Naejeon area.