Abstract: An optimal water dispatching model for landscape water quantity and quality has been developed and applied to Tianjin Coastal New Area, as a case study, to meet the demand on maintain urban landscape water quantity and quality and achieve high economical efficiency of water operation and maintenance. The present study shows that this model is able to minimize the daily cost of urban landscape water operation and maintenance under the condition of reasonable operation parameters such as the volume of water replenishment and the periods of replenishment and circulation. The results are helpful to optimization decision on the technical schemes of urban landscape water treatment, water quality management, and water operation and maintenance.