Summary - The 20^th century has seen the evolution toward systems of mass higher education in almost all advanced countries. No less than 50% of each age cohort is entering some institution of higher learning. The quantitative expansion of the student body challenges the structural features of each system. The traditional humboldtian model of the European university no longer meets the requirements of mass university, but the need to safeguard quality of teaching and research is felt by public opinion and policy makers everywhere. The trend is toward increased differentiation within the system. The North-American model aims at the market regulation of both access to resources and assessment of the value of degrees granted. The British model establishes a hierarchical grading of the various institutions. The French model differentiates between hautes écoles and universities. In Italy the rigidity of the systems prevents until now a real competition between institutions for access to resources and for recruitment of high quality teaching staff and students. The tendency to strengthen the autonomy of each establishment and to create "poles of excellence" is a very recent development whose success or failure has yet to be assessed.