The significance of this study is the demonstration of a new method of preservation procedure for national-treasure-class cultural-assets by examining the characteristics of the Jeogori relic, presumed to be that of King SeJo, and validating the preservation process. This Jergori as well as the wooden Munsu-donja Buddha statue from which they were found are designated as national treasure. The Jeogori relic is made of light silk and dimensions mark 77 cm in length, 67 cm in width, and 94 cm in sleeve length. It is a typical Jeogori worn in the Chosun Dynasty. Preservation procedure was in the following order: Removing dust and pollutants by vacuum, washing, removing creases, reinforcing the clothes, settling at paulownia backboard, and packing. Storage and exhibition of remains was executed with as minimal folding as possible, and microbiological damage prevention was performed by dyeing antibacterial treatment with eugenol onto supporting cloth. The relic, conservatively treated in accordance with the above procedure, is currently kept at the storage facility of the citadel Museum in the Woljeong Temple. It is displayed annually to the general public for approximately two weeks.