Those magnificent large temples in Eanna Precinct at Uruk, which had highly developed during the Uruk period, completely disappeared at the point of transition to the next Jamdat Nasr period. In the “Zwischenschicht” there were more than fifteen troughs dug into the ground for the purpose of purification of the whole sanctuary by the “Brandopfer”. In this new phase (Uruk-III Stratum) the High Terrace was the only imposing construction relating to the religious rituals. Other structures were composed of many small rooms, courtyards, and corridors. This great change was performed in such a short term that there must be taken into consideration of the existence of the powerfull leaders who could control both a mass of man-power and financial ability. The “Stampflehmgebaude” (100×120m2) newly excavated westward the High Terrace may be the largest building in Eanna Precinct through the J. N. period. Compared with the palaces in the Early Dynastic period, I would like to find some clues as to whether this gigantic labyrinthian building was the oldest “palace” in early Sumerian City-States.