This paper is devoted to study the formation of the historical center of the city of Mecca from its beginning to its formative stage that, in my view, took place by the extension of the Abbasid Khalifa al-Mahdy, where its architectural identity was formed and marked its order in space. This paper will focus upon the purpose of choosing the site of the city, the conditions of living, the process of formation of the historical center and its urban context. It will argue that the holy shrine (al-Ka`ba الکعبة) and al-Masjid al-Haram, were and still are the major elements that governed the development of the historical center and the urban planning of the city of Mecca. Furthermore this paper will prove that the historical center of Mecca was reduced in those two elements. This paper will also demonstrate that key architectural concepts and notions - like: centrality, architectural identity, order in space and public participation were coined within the formation process. So much so this paper will disclose the techniques of conservation and preservation that were coined, too, in the said process like: replacement of material, demolishing and reconstructing, protection and credibility. In so doing an attempt will be made to explore the role of the holy Quran in setting out the site of the historical center and documenting the process of building al-Ka`ba. And the contribution of al-Azraqiy in his book Akhbar Mecca and other related sources, in recording and documenting the construction and reconstruction of al-Ka`ba. And the extensions of al-Masjid al-Haram, in order to explore and highlight the architectural key concepts and techniques of conservation and preservation. Badi Al-Abed, “The Formation Of The Historical Center Of  Mecca".- Historical Kan Periodical.- Issue (21); Sep 2013. Pp. 196 – 201.