Kim was an extremely gifted child and had picked up reading ability at eight months of age.

Kim wrote the first novel in Classical chinese in Korea, titled Geumo Sinhwa (금오신화; 金鰲新話), as well as other books such as Siphyeondamyohae, Tangyugwanseorok, and Tangyuhonamnok.

Although Geumosinhwa was influenced by a Chinese novel titled Jiandeng Xinhua (New stories while trimming the lampwick) by Qu You, it would become nativized.

It appeared in several books of his that the king and subjects should respect the whole nation regardless of a person's status and origin.

It was believed his thought was much advanced compared to the era in which he lived and remained one of the earliest ideas concerning democracy on the Korean peninsula.