The objective of the study is the analysis of catalonian universities scientific production in the period 2000-2004. It has been calculated indicators by university about scientific activity, visibility, impact, power research,
citation, selfcitation, regional and international collaboration. The empirical evidences show a stratified university system, without a clear specialization in their activities of research. The network of international collaboration by countries with Catalan universities has been drawn graphically. The universities as a whole prefer to collaborate with the United States, the United Kingdom, France, Germany and Italy and obtain better visibility when they sign his works with authors in English language.