This study aims to investigate the history of Giroso during the early Joseon Dynasty, examine the authenticity of the history regarding Taejo's admission to Giroso, and identify the background and architectural form of Giroso Youngsugak. Research confirms that Taejo joined Giroso in 1394 at the age of 60, but there is no evidence of his name being recorded in the Giroso Seoru. Giyeonghoe(耆英會) has been frequently suspended since the 16th century, and after the Japanese Invasion of Joseon in 1592, the king's permission for Giyeonghoe was not readily granted. Taejo's admission to Giroso and the story of Giroso Seoru started emerging as a justification for resuming Giyeonghoe. When King Sukjong joined Giroso, a new building called Youngsugak was required to enshrine Eochup(royal writings), and it was modeled after Jongbushi Seonwongak. Although Youngsugak no longer exists, the form of Giroso Youngsugak from the past can be observed through Uiseong Gounsa Yeonsujeon, which was constructed in 1904 based on the model of Giroso Youngsugak.