The writer of Gong-hu-in and the year when it was written has not been demonstrated yet. This work is translated in sino-Korean and recorded in various books. The writer of the Gon-hu-in is largely assumed as the following two persons: wife of Baek-su-gwang-bu and Yeo-ok, a wife of Gwak-ri-ja-go. It is named as Gong-mu-do- ha-ga as a poem which is thought to be written by a wife of Baek-su-gwang-bu. And it is named Gong-hu-in as a song whose writer was thought to be Yeo-ok. In various perspectives, this study concluded that the writer is Yeo-ok, but when it considered as a poem named Gong-mu-do-ha-ga, it is written by Gwak-ri-ja-go, husband of Yeo-ok. The above result was obtained through consideration of progress of events, roles of heroes, subsequent situations, and reinterpretation of background story. Therefore, Gong-hu-in as a name of song is written by Yeo-ok, and a poem named Gong-mu-do-ha-ga is written by Gwak-ri-ja-go. That is, it is a work written by the couple(husband and wife).