"In all religions, the first act of man is to insure his place where he lives. This act, in fact is a gesture that sometimes obeys to an unconscious law which are governed by a tradition whose souvenir has been lost. The human settlement which is the object of this study is the Ibadhite city "K'sar". If we try to look at these cities in particular, we are then susceptible to notice a series of traditions (inspired by the Islamic religion) that sometimes speaks to the spirit than the written one. The interaction between the whole of legal dispositions "La Shari'a" (religious law,) and the construction process has created a model of urban and architectural traditional culture. This model of urban and architectural culture typically Islamic covers notions related to a particular space organization coming from precepts of Islam as a revealed laws governing the life in its totality and especially that of the Ibadhite K'sar (the city) assembly place of all the believers. The objective of this study is to know and to identify the knowledge that has produced this architectural and urban traditional culture, then to see how to apply it on the contemporary city to insure a positive experience continuity and inheritance of the past. The used approach to reach the objectives, mentioned above was influenced by the investigation of ancient documents, notably the ancient manuscripts and historical annals, this approach rests essentially on two types of investigation: (1.) Study and investigation of the ancient manuscripts and historical annals that can put the light on the construction process of the Ibadhites K'sar (city), here the areas of the fiqh (Islamic law), Urf (common law) and Shari'a (revealed law) have proven their efficiency to lighten and at the same time to solve raised problems in the course of the construction process ofthe Ibadhite K'sar. (2.) Urban and architectural analysis of the Ghardaia K'sar that has no sudden large changes, to see how the social value system, the regulation system and the inspired legal positions of Shari 'a, have changed the framework of the built form of the lbadhlte K'sar."