This article describes the contribution of Dutch sociologist Saskia Sassen, whose research topics include immigration, cities, and the changes in the liberal state. It takes a general look at her work in order to systematize her main contributions. The objective is to use an essential analytical mapping to highlight the complexity of globalization, with its antagonisms and contra-dictions, that Sassen explains to demonstrate not only the growing interde-pendence among countries in the formation of exclusively global institutions, but also identify the globalizing dynamics inside the institutional and social sphere of the national, where national and non-national elements combine.