"This study is part of a research work on urban transformations of the historic centers in the Algerian cities of colonial origin. These centers, previously designed as cities for French population, are now appropriated by Algerian population and become down towns in today's cities. Setif, as a case study, is a typical example. In general, it is established that the contemporary city in the West draws its legitimacy from its historical roots. Whereas the contemporary city of colonial origin in developing countries like Algeria, seems to have its historical core rather balancing between heritage and patrimony. Though people and values have changed, this core remains the permanent city center where people likely find the urbanity they need. Concerning this "patrimony", visions and attitudes are not shared by the different actors involved in the urban transformation process. Although its usage value, this colonial heritage is undergoing a fast deterioration process. The problem of identity is more acute in Algeria than anywhere else, it is thus necessary to approach the issue of heritage and patrimony in a different way where every actor can play his role and participate in shaping his living environment. An insight evaluation of this urban and architectural production may help to identify 'value indicators' allowing a contemporary vision towards this heritage. Then, the issue will be how to preserve this heritage or patrimony. Our research strategy is based on the typomorphological analysis of the transformed plots and buildings of the colonial period combined with the study of the usage and significance of urban life for the Setifians. Finally, the role of every actor will be investigated and the extent of users participation will be addressed."