This study analyzes the effectiveness of the cleaning methods applied to the Korean Youth Baseball Tournament championship flag, Korean cultural asset no. 498, which is currently owned by the Korean Sports Council. This championship flag was first given to the winning baseball team during the Chosun National Athletic Meet in July, 1920 and therefore carries importance in Korean sports history. The conservation process began with the following goals: to understand the current condition of the relic, to reduce the soils, to repair and reinforce the deteriorated areas, and to prevent further major damages to the relic