Baeja(背子), which was excavated from the tomb of Sim, Su-ryun(沈秀崙, 1534-1589), a civil official, has a distinctive pattern. Two rectangles are connected by button knots on both shoulders and below the armpits, and surround the front and back of the upper body. Also, the back is shorter than the front, while the center-front is not opened. It also has a round neckline without a collar. Jeojuji(楮注紙), which is a traditional Korean paper made from mulberry bark, is put between the outer shell and lining of this clothing as an interlining. The purpose of this study is to perform a morphological feature analysis of the Baeja to examine its characteristics and name, and clothes with similar features, attire relic, pictorial and ceramic materials as well as precedent studies were used in the analysis. The Baeja, which was excavated from the tomb of Sim, Su-ryun, has the same pattern as Yangdang(??), which was worn in the ancient northern region and China. Its composition and the way it was worn are very simple. Also, the shorter back length can be used as evidence that it was worn as everyday outer clothing, and not in a ceremony. Jeojuji, used as an interlining, made it easy to sew and maintain attire pattern and played a role of maintaining warmth. Therefore, this Baeja is presumed to be an outer clothing simply worn in the everyday life for convenience and warmth. In regards to its morphological feature, it was most likely a Yangdang in Joseon Dynasty.