The purpose of this study is to investigate the revision of the western-styled court costume in the Daehan Empire. For this purpose, 1) historical documents were reviewed, 2) one set of the court costume of Chigimgwan and another set of the court costume of Juimgwan were probed, 3) the photos of people wearing court costume were analyzed. The results of this study are as follows. First, the $14^{th}$ Imperial order of "official costume statute" had been revised in 1904, 1905 and 1907 through official gazettes. The last version of official costume statute enacted the more detail than the first rule. Second, the $15^{th}$ Imperial order of "official costume rules" had been revised in 1904, 1905, and transformed into official costume rules reform on $12^{th}$ Dec., 1906. The revision in 1905 made gold embroidery of court costume more simple than the first rule. The form of court costume was totally revised by change of the shape of adjusting on the top in the revised rule of 1906. Third, the revision in 1905 was actually manufactured and worn by the people because it can be confirmed in the relics of the court costume of $2^{nd}$ Chigimgwan in Yonsei University Museum, and the court costume of juimgwan in Kwangju Municipal Folk Museum. The relics made by the revision in 1906 had not been reported until now, but they can be confirmed in the photos left. Fourth, the sovereignity of the Daehan Empire was actually lost by $22^{th}$ Imperial family order which urged the servant having the title of nobility of Japan to wear the court costume of Japan. Therefore, the endeavor of the Daehan Empire which wanted to establish and develop the costume system of modern independent nation was discontinued.