Within the Algerian context the urban historical centers are mainly composed by the old city of Ottoman era and the European city of the French era. These urban centers have experienced and continue to experience significant changes in their units, homogeneity and urban image. This phenomenon is accentuated with the natural growth of cities and the rural exodus. Therefore, urban development has complied with the economic imperatives alone, ignoring any historical urban structure reflecting the richness of different civilizations and cultures in the country. During the French period (1830 - 1962), the city was mainly inhabited by the Algerian population concentrated in the neighborhoods of the traditional city "Medina", and a European population concentrated in the colonial-type of houses. The city of Constantine which is considered the capital of eastern part of Algeria, by its size, its history and geographical position has seen many changes related to its structure and urban image. Also the city continues to undergo major transformations disregarding the context of historical urban city. Several scientific studies and research have allowed us to express the magnitude and importance of evaluation studies in the field of preservation of architectural heritage. Therefore, it is urgent to undertake scientific search in order to highlight the interest of this historical memory.