Yugasajiron is one of 4 pieces of Chojo Tripitaka among Song Sung-moon’s donation. When Kitan intruded into Gaegyeong in 1011, Goryeo King Hyeonjong ordered Chojo Tripitaka to be made. It was completed in 1087, but it was burnt in a Mongolian invasion. The prints of Chojo Tripitaka that have been handed down until now, are approximately 2,600 books, most of which are in Japan. The number of its prints found in Korea now is about 200 and most of them are registered as Treasure or National Treasure. Chojo Tripitaka not only followed the Tripitaka of the Song Dynasty but also exhibited unique Korean printing techniques by adding scriptures that had been left out.