Excavations of Silla royal tombs have produced no tombstones or other decisive information on who was buried there. This study attempts a new interpretation in consideration of the size of burial mounds, their locations, quantity, and quality of grave goods, etc. For instance, it reveals that the diameter of royal tombs shrank greatly from 70 meters in the 5th century to 50 meters, as in the tomb of Maripgan (the title borne by Silla kings) Jijeung. This confirms a gradual change in the royal tombs and tomb system through the middle Silla period. Based on these findings, it assumes the existence and locations of major Maripgan tombs among the old tombs across the Daereungwon Tomb Complex in Gyeongju.