This thesis studied the costumes of Gwan-Rye(관예). the lowest ranking officials of Yi-Dynasty. It researched the written materials and compared it with relics of Gwan-Rye costumes. The gists of the result are; 1) The Koryo tradition of Gwan-Rye costumes continued until the early days of Yi-Dynasty. 2) The Gwan-Rye costumes can be classified into two styles. One is Sa-Ryung(사영) style, which consisted of Dan-Ryung(단령) robe and Jo-Geon(조시) as head gear. Na-Jang(라장) style. the another, consisted of Dan-Ryung. Ban-Bi-Ui(반비의) and Jo-Geon. 3) These styles changed around the days of Yeon-San(연산), the 10th King of the Dynasty. The Na-Jang of later days wore Cheop-Ri(첩리) robe instead of Dan-Ryung. And the Sa-Ryung costume was devided into three different styles. They are (1) Gat(립)- Cheop-Ri (2) Bung-Geo-Ji(단립)-Chang-Ui(창의) (3) Gat- Kwoe-Ja(쾌자) styles.