The political Capitals that ruled Anduls before Islamic Arab opening ,left many military architectural institutions, as castles, walls. The Arab Muslims used these institutions and entrenched inside them during the opening process.However, the Arab Muslims did not limit themselves to what they found in the Andalusian country of military architectural facilities, but they built new facilities and reinforced the defense supplies that were in the walls of the fortresses and castles. This research has been divided into two sections, the first was devoted to the cities which Arabs have established in Anduls for military purposes. It is also included the instituting defensive wall. While the second chapter has focused on fortresses, castles, towers, towns and other military architectural installations that existed before the Islamic conquest, which was built after the conquest. This study sought to trace the construction of architectural military installations in Andalusia during the Arab Islamic rule of Andalusia.