Jobok (朝服: official court attire) is official attire worn for official morning meetings between monarchs and servants. It was also used for various official ceremonies throughout the Joseon Dynasty. Official uniforms of the Joseon Dynasty were categorized into four types based on their purpose: ceremonial, court, public, and daily. Among these, Geumgwan-Jobok, which included a Yanggwan, was a ceremonial uniform worn by the royal family and high-ranking officials on special occasions. It was worn throughout the Joseon Dynasty. In the early period, all officials from the 1st to ninth ranks wore it, but later, the ranks were reduced to fourth rank or higher. Later, those excluded from wearing Geumgwan-Jobok wore Sangbok, or black Danryeong with a chest insignia attached, as Jobok. This phenomenon is expressed in various documents as “Jobok for fourth rank or higher, black Danryeong for fifth rank or lower.” To date, research on Jobok has been conducted in considerable depth. However, there has been no research on the change process in which official uniforms were established as “Jobok for fourth rank or higher, black Danryeong for fifth rank or lower” in the 17th century. It can be confirmed by understanding the current status of officials wearing Jobok when participating in various state ceremonies. In addition, it is necessary to study the specific status of officials wearing Jobok during state ceremonies. Against this backdrop, this study aims to analyze the current status of wearing Jobok in the 17th century, using literature on state ceremonies in the late Joseon Dynasty as the basis. The results of analyzing a total of 32 ceremonies held in the Joseon royal family from 1604 (37th year of King Seonjo’s reign) to 1696 (22nd year of King Sukjong’s reign) are as follows. Jobok, worn by all officials from the 1st to ninth ranks when Joseon was first founded, was not completely abolished until the first half of the 1600s. It was confirmed that the fourth rank and higher maintained Jobok while those from the fifth rank and lower were divided into black Danryeong starting in 1651.