Although Un'yeong-jeon is a highly important work in the history of Korean classic novels, its author remains unknown to date. Through in-depth historical research this paper reveals Un'yeong-jeon was written by Seong Ro(成輅, 1550-1615). Another work of Seong Ro is Seokjeonyugo, which is analyzed in this paper together with Un'yeong-jeon and the documents left by other writers of the time. This analysis has reached the conclusion that Un'yeong-jeon was written by Seong Ro.
He is a descendant of Seong Sam-mun, one of the “six martyred ministers.” Identifying Seong Ro as the author of Un'yeong-jeon finally explains why Seong Sam-mun appears in the work, as well as the reason why Grand Prince Anpyeong is depicted so positively.