This study has examined existing studies and their problems of the royal army among Goryeo military organizations. Although there have been unresolved problems such as vague understanding of the term, Geunjang, a critical ground to see Igun as a kind of the royal army, the military balance of power between Igun and Geumgun, and the total size of Geumgun. it seems that Geumgun, as a special force, was the royal army. It is proved by the facts that Geumgun included several individual forces such as Gyeonyonggun, that there were some peculiar title, such as Jiyu and Haengsu in officer positions of Geumgun, that the people who held the positions of Jivu and Haengsu came from various human sources, that three Guns, six Wis, and 42 Dobus were described in Gunbusajungsincheongsagi of Jolgocheonbaek written by Choi Hac, a typical high-ranking government official in the late Goryeo period. and that there was a difference in time over the period of the establishment of Igun and Geumgun. The future study will have to distinguish between Igun and Geurngun as the central army in Gorveos military structure. Igun which included local forces also could be seemingly regarded as the army of the king, the highest commander-in-chief. But Geumgun was a quite different military organization from Igun in its duty and character, and could be considered the royal army of royal forces.