This study investigates the background, contents, and choreographic style of the Mudong (舞童) Jungjae (呈才) performed at the 50th birthday banquet of King Soonjong, the last emperor of the Korean Empire. Gainjeonmokdan (佳人剪牧丹), Jangsaengboyeonjimu (長生寶宴之舞), Yeonbaekbokjjimu (演百福之舞), Mugo (舞鼓), Pogurak (抛毬樂), Bosangmu (寶相舞), Suyeonjang (壽延長), Chunaengjeon (春鶯囀), and Cheoyongmu (處容舞) were performed at the banquet held on March 25, 1923, on King Soonjong’s birthday. Among them, Cheoyongmu was excluded from this study, as it was separately studied and performed by Aaksu (雅樂手) and five physically fit Aakseng (雅樂生) students from the first-year class of the Aakdae training school. Thus, this study examines eight Jungjae dances that were performed by Aakseng students who were selected as Mudong. The Korean Empire was colonized by Japan on August 29, 1910; following this, King Soonjong’s daily life was restricted through the control of Iwangjik (李王職), or the Office of the Yi Dynasty. This study examines Jungjae dances that were studied and performed by 11 Aakseng (雅樂生) Mudong; these were hastily put together for the 50th birthday of King Soonjong. Aakseng boys aged 13~19 years, who joined the Aakdae (雅樂隊) training school as the first-year and second-year class in the early winter of 1922. were abruptly enlisted to learn Jungjae dances. After five months, they performed for the king. This launched the dancing careers as Mudong for Aakseng students at the Aakdae training school within Iwangjik. The dances performed at the 50th birthday banquet of King Soonjong were mostly createdin 1828 and 1829. The story of these Jungjae dances included ① the love between husband and wife and ② a wish for the longevity and prosperity of the country. In addition, they comprised ③ entertaining elements that combined a wish for longevity with amusement, completing the broad variety of the dance. By the 29th year of King Gojong’s reign or the Imjin year of 1892, and following their performance at the 41st birthday banquet of King Gojong, the number of dancers for the Mudong Jungjae performance was finalized. The choreographic styles of the eight dances are discussed in greater detail below. The Mudong Jungjae of the Joseon Dynasty is said to have been passed down with great difficulty under political and cultural oppression during the Japanese colonial era. In this study, we propose to lay the groundwork for establishing a proper historical perspective on the dissemination of traditional dances through consideration of their background.