Abstract: Artificial water replenishment is important measures to restore the health of urban river and lake ecosystems and to improve urban landscape． To achieve the goal of water quality maintenance, biodiversity, recreation, and navigation of small cruise ships, in this paper a water demand estimation method was developed for urban rivers and lakes in the absence of any observed data． Existing studies at home and abroad were studied, key control factors (such as velocity of the river flow, water depth and water change cycle) were determined, appropriate value range of key control factors was proposed． This work will provide references for water demand estimation in related research and practice of artificial water replenishment．