This volume contains the proceedings of ICCS 2003, the 11th International C- ferenceonConceptualStructures. Thisconferenceseriescontinuestobethemain forum for the presentation and discussion of state-of-the-art research on conc- tualstructures. Thetheories, methodologies, andtechniquespresentedherehave grown considerably in scope in recent years. On the other hand, solid bridges spanning the boundaries between such diverse ?elds as Conceptual Graphs, F- mal Concept Analysis, and others are increasingly being built in our community. The theme of this year's conference was "Conceptual...