The book constitutes the refereed proceedings of the 11th International Conference on Conceptual Structures, ICCS 2003, held in Dresden, Germany in July 2003.The 23 revised full papers presented together with 5 invited papers were carefully reviewed and selected for presentation. The papers are organized in topical sections on the many facets of conceptual structures, logical and linguistic aspects, conceptual representation of time and space, deepening the formal theory and applications of conceptual structures.