Examining the marriage relationships of the Silla kings in the 5th and 6th centuries as seen in Samguk Sagi and Samguk Yusa, they married Queen Kim in the 5th century. However, after King Jijeung's reign, Queen Park appeared and continued to the Jinji Dynasty. After Prince Dongryun, the son of King Jinheung, married Lady Manho, who is Kim, Queen Kim appeared again. In other words, except for marrying Queen Park for three generations after King Jijeung, it took the form of Kim's same-surname marriage or tribal endogamy and consanguineous marriage. In this regard, many previous studies understood that this endogamy was made for the purpose of maintaining the sacred appearance of the royal family, and that Queen Park appeared due to King Jijeung's emergency accession. However, this was due to the characteristics of the Silla's Bu-system. From the perspective of Bu-system theory, it can be confirmed that the queens of the Maripgan period were the daughters of King Galmun from Satakbu, and all the queens after King Jijeung's reign were Park from Moryangbu. Based on this, we can understand two things: the kings from Takbu got married women from Satakbu for generations, and King Jijeung, Beopheung, and Jinheung from Satakbu married women from the different Bu, Moryangbu. This implies that the marriage custom of Silla's royal family was not endogamy but exogamy based on Bu-system, which was the same as the custom of Goguryeo and Baekje. It means that the marriage custom of Silla's royal family also did not deviate significantly from the form of tribal exogamy and class endogamy which is commonly found in world history. Meanwhile, many researchers were interested in two subjects: the reason why Kim Chun-chu was Jin-gol(True bone), and whether he was already married when he was in a relationship with Kim Moon-hee(Queen Munmyeong). Marriage between Kim Yong-chun and Lady Cheonmyeong was likely class endogamy between children of concubines of King Jinji and King Jinpyeong. This may naturally explain why Kim Chun-chu was Jin-gol, not being Seong-gol(Sacred bone). And because there were some difficulties in accomplishing the marriage between Kim Chun-chu and Moon-hee, it is commonly believed that Kim Chun-chu already had a wife before he met Moon-hee and Gotasorang, who died with Kim Pum-seok during the battle at Daeyasung, was the daughter of Kim Chun-chu's first wife. In this paper,however, I pointed out the problems with these understandings and inferred that Gotasorang was the daughter of Kim Moon-hee.