Recently, the process of urbanisation has radically mulated. The new contemporary parameters, like informational technology, the neotertiary economic sector, and the globalization process require a major revision of the urban models with wich we operate, and wich are still a reflection of the old paradigms resulting from the industrial revoluction, the mechanical technology and the single-saclae nation-state. Urban space is more and more an open, dynamic, and comprensive system, which makes possible to identify different urban realities inside the same city. A new language and new theoretical approaches must be developed in order to understand present-day urbanization processes. As a consequence, the USUM -Urban Systems and Urban Models research project aims at investigating present-day urbanization processes in their actual complexity. Two main issue in particular have been addressed by the USUM research project:1 the development of a multi-scalar and comparative approach for empirical research in the urban field both in socio-political and environment terms; 2 the analysis of the transformation of urbanization processes and urban / public space.