This book studies the urban logistics system from the perspective of reliability, based on the theory of urban logistics and system reliability, with the research of urban logistics system reliability as the main line, with matter element analysis and ant colony algorithm as the main research tools.  On this basis, this book closely focuses on the connotation, influencing factors, measurement, optimization, and other issues of the reliability of urban logistics systems.  By analyzing the influencing factors and constituent contents of the reliability of urban logistics system, the reliability measurement is researched, and the reliability optimization model of urban logistics system is established, which is suitable for popular science reading or in-depth study by readers with a certain foundation.