By using the research methods of literature and historical analysis, the paper investigates the festival sports customs in Korean Peninsula on the basis of historical data of ancient Korea. The research shows that festival sports customs of Korean Peninsula concentrate on festivals such as the Lantern Festival, the Double Third Festival, the Dragon Boat Festival, the Double Ninth Festival and the New Year’s Eve, and they are more popular especially in the Lantern Festival and the Dragon Boat Festival, which were important parts of the festival sports customs in Korean Peninsula. Festival sports customs in Korean Peninsula have the characteristics of strong Chinese color, strong martial spirit and distinct character of the farming culture.