This article introduces the Korean “vulgar characters” recorded in the “Jaseo Jibyo” (《字書輯要》) written in the late Joseon Dynasty with the addition of Dong-vulgar corrupt characters (referred to as “Dong-su characters”), and to clarify its academic significance for the purpose. The article contains a total of 117 vulgar Chinese characters, which were probably written in the late 19th or early 20th century. It includes various common and special characters that were seen at that time, so that we can understand the use of common characters in the late Joseon Dynasty. For this reason, this article has made the “Popular Characters”, and compared with the square-printed edition “Shiwencuo” which preserved the alien society at that time, and obtained the universal use of the common characters. The “vulgar words” are divided into four categories: “①omit, ②add, ③replace, and ④symbolize”. Then, taking the characters (國guo), 伩(儒 ru), and (聖sheng) as seen in the “Dong-vulgar characters” as examples, the cultural awareness hidden behind the characters is analyzed in detail, in order to navigate the cultural research of variant characters. Attached is the “Popular Character Catalog” attached to the “Manuscript Addition and Deletion of Yeomlag Pung-a”(《增删濂洛風雅》) collected by the author for comparison and reference.