This articles aims to arrange the problems rhar are exposed from Saribonganki (사리봉안기) discovered in early 2009. Above all, how we interpret a Seodong story(서동설화) in Samgukyusa(삼국유사) is most important. Until recently, we have paid little attention to how much the srory reflects the historical faces. I deal with the political relation between King Mu and Sa family. Two powers had kept up close conracrs, bur their relations deteriorated gradually. The result was that King Yeuja(의자왕) got rid of Sa family shortly after the death of King's mother. The Miruk temple(미륵사) was constructed after the pattern of three Buddha temples and three pagodas. Some argue that Sunhwa Prin(선화공주), supporter of the Surra of Lorus faith. built a Buddha temple in the centers, and the daughter of Sa family, supporter of the Maitreya faith, built rwo Buddha temples in the east and the west. Others argue that three Buddha temples and three pagodas were built under the same plan. There are also historians who emphasize that the supporters of rhe Maitreya faith in Iksan were in conflia with those of the Sakyarnuni faith. Finally one insists that the five-storied pagoda in Wanggungri(왕궁리) was built in the 7rh century. However all these opinions lack clear evidences. It is necessary to make a more detailed investigation.