This paper analyzes the process of the institutional change of penitentiary policies in a context of political crisis. It focuses on the impact of political transformations on the orientation of public policies. This analysis is based on four political situations of the 1990s: German reunification, the fall of the Soviet Union, the abolishment of apartheid in South Africa, and the efforts of democratization in Turkey. In order to move beyond the classical dialectic of continuity and change, this paper”which is based on the research carried out by P. Hall”aims to differentiate the forms and the levels of change. The comparison of a certain number of variables reveals differences between instruments of action, the orientations of public policies, and paradigms.