The stylobate for expanding the external stage area was the most frequently installed installment out of the installments installed for royal court ceremonies. The stylobate was installed for various ceremonies such as funeral rites, ancestral rites, customary formalities, state examination, feasts for celebrating a honored guest of the court, queen’s silkworm cultivating ceremony, heir appointment, the presentation of honorary titles for the king or queen in honor of their merits, and entertainment of foreign dignitaries. The exact period stylobates came to be used for the play stage. The stylobate consists of the 紅座板, 屯太木, 竹欄間, 足木, and the 層橋. Depending on the 足木, the substructure of the stylobate, the stylobate could be divided into the 長足木, 中足木, 短足木, 平足木type. The detail structure of the stylobate changed in form from the jokmok and duntaemok that appeared until the time of King Seonjo, into the 長屯太木, 短屯太木, and the 短短屯太木 during the time of King Heonjong. With the introduction of the 中足木, materials began to become more segmented and the structure stronger. According to existing records, while the height of the stylobate was not significantly high prior to King Seonjo’s reign, the 十四層雲橋and the 十三層層橋introduced during the time of Emperor Gojong was designed to reflect his rank in external ceremonies while the eight story step bridge was exhibited in internal ceremonies to reflect the rank of Queen Mother Sinjeong. From here, we can deduce that the fourteen and thirteen story cloud bridges representing the king was of a higher grade than the eight story step bridge which represented the queen mother. Finishing by adding boards to the lower part of the stylobates began to appear in the time of King Seonjo. During King Heonjong’s reign, the lower finish became gentrified with a thin board called 修粧板, and yeomupan 廉隅板for decorating the edges of the stylobates were installed. Such style of finishing the lower part of the stylobate with boards mostly appeared in elaborate feasts 進饌and celebrations 進宴within the royal court 內宴. The stylobates appeared to have served not only practical purposes such as expanding the stage area, but also as installments which realize the authority and prestige of the royal crown. They were installed according to the purpose of the ceremony and the rank of the participant. In short, stylobates became established during King Seonjo’s reign, became segmented and gentrified during King Heonjong’s reign, and began to take height variations during Emperor Gojong’s reign to reflect the rank and authority of the king and queen mother. As such, it can be considered another characteristic of Joseon Dynasty architecture.

This study aims to analyze functions and characteristics of 'Cha-il(遮日)' which was used at ritual events(宮中儀禮行事) in the Joseon dynasty, Joseon dynasty had many ritual events related with O-Rae(五禮). Cha-il was almost used at important ritual events, especially at the congratulatory events. The congratulatory events(宮中宴享) are the representative events were held with many temporary install facilities(假設施設) in a palace. Cha-il was a kind of Korean traditional membrane structures. Cha-il was set up for cutting off interior space from sunlight and rain. In general, Cha-il was Consisted of Cha-il-jang(遮日帳:woven fabric), Cha-il-jook(遮日竹:bamboo column), some ropes, and fixing wares. In the congratulatory events, three types of Cha-il. were set up. Baek-mok-Dae-Cha-il(白木大遮日)was made of cotton cloth. Yu-Dun-Cha-Il(油芚遮日) was made of oiled paper or oiled cotton cloth. Man-Joen-Cha-Il(滿箭遮日) consisted of wooden structure. Baek-mok-Dae-Cha-il(白木大遮日)was set up on the most important area of stage for protecting from sunlight. Yu-Dun-Cha-Il was set up on less important area of stage for protecting from sunlight and rain. Man-Joen-Cha-Il was set up below Baek-mok-Dae-Cha-il for supporting and draining raindrops off. The results of this study were as follows; Functions of Cha-il were to protect ritually space from sunlight and rain, and to extend ritually space, and to reconstruct ritually space. Cha-il was the peculiar temporary install facility which differed from other countries.