This book constitutes the refereed proceedings of the 10th International Conference of Z Users, ZUM'97, held in Reading, UK, in April 1997.The volume presents 18 revised full papers together with three invited presentations by internationally leading experts. The papers are organized into topical sections on real-time systems, tools, logic, system development, reactive systems, refinement, and applications. Also a select Z bibliography by Jonathan Bowen is added. All in all, the book competently reports the state-of-the-art in research and advanced applications of the Z notation.