中文摘要：

文中研究了中国古代城市水系各个方面的问题，包括城市选址与江湖水系的关系，城市水系的规划建设，城市水系的类型，古城的奇葩——水城．特别指出了城市水系的十大功用：供水、交通运输、溉田灌圃和水产养殖、军事防御、排水排洪、调蓄洪水、防火、躲避风浪、造园绿化和水上娱乐、改善城市环境．文中还指出，城市水系在促进城市的繁荣发展上有稳定城址、促进工业发展、提供较高质量的生活居住环境的重要功用．并指出，城市水系在形成城市特色方面的重大贡献．文中批评了现代城市建设对水系的破坏，指出只有加强城市水系建设、管理和保护，才能体现名城的特色，建设兼有传统和现代特色的现代化城市．

英文摘要：

This paper intends to study the urban canal system in ancient China in several important aspects, e. g. the waterways influence on site selection of cities, the planning and construction of urban canal systems, the types of the layouts and the features of ancient water cities, etc. Ten major functions of urban canal systems are summarized, including water supply, waterborne transportation, irrigation and aquaculture, military defense, draining of floods and waste water, flood storage and mitigation, fire fighting, ship sheltering, landscaping and recreations, as well as environment tempering. The paper provides rich examples to demonstrate the significant role that urban canal systems play in stabilizing urban sites, promoting industry and commerce development, and improving living environment. By citing typical cases both at home and abroad, the author shows his disapproval of the destruction of urban canal systems in the course of modern urbanization, and emphasizes that urban canal system is one of the most important embodiments of a city. It is concluded that the existing urban canal systems should be well conserved so as to present unique urban outlooks characterized by both tradition and modernity.