This thesis aims to examine the historical background of Chiso Fortress in Keumju, with an approach to its spatial features utilizing the achievements of relics recently found there. Academic materials and archeological researches indicate that the fortress was founded during the Era of Unified Silla, with its origin dating back to the establishment of Garak Dynasty’s capital. Inner spaces of the fortress were found to be tight competition fields among clan leaders over local power as well as dynamic living grounds in which various members inhabited. As a representative center of administration in the southern parts of Kyeongsang Province, Chiso Fortress was a vivid contrast to other fortresses in the local communities in terms of its position in autonomy, administration, taxation, security and military affairs. Main administrative areas for essential functions running over 5 km around the fortress were the avenues between the tomb of Gaya founder, a sanctuary site, and Hogye which connected southern and northern routes. As the bases for various marine activities around its southern parts leading to the ports in the bay, the fortress had some features of port town. Geographically located at the strategic center for the sea and land, Chiso Fortress could no longer fulfil its functions due to the fierce attacks from Japanese pirates in the late Goryeo Dynasty. During its following dynasty of Choseon era with its center in the Asa Avenue, it was degraded into a small local fortress, recovering its minimum functions. We, thus, can not expect the old aspects of Chiso Fortress of Goryo Dynasty any longer.