Urban forests play a significant role in urban development because it provides valuable ecological and environmental services, landscape integrity, and recreation opportunities for urban residents. However, water saving approaches for urban forest development must be adopted in the cities that are facing water resources shortage. Many studies suggested that forests have much higher water demand than shorter plants. Therefore, it is critically important to select water\|saving trees in urban forestry practices in order to achieve the sustainable urban greening and landscaping. We selected four major urban tree species including Cedrus deodara，Zelkova serrata，Euonymus bungeanus，Metasequoia glyptostroboides.to quantify whole tree water use in the Labor Park of Dalian City, Liaoning Province, China. Thermal Dissipation Probes were deployed to monitor the sap\|fluxes continuously for 12 trees, three DBH classes of each species, from June through October in 2008. Climatic variables and soil moisture at the depth of 0-25cm, 25-50cm, 50-75cm, and 75-100cm were also measured by an automatic weather station and EMS70 soil moisture probes at the same time, respectively. The remarkable diurnal\|nocturnal variation of sapflux for different species was observed during the growing season and the nocturnal water loss accounted for a certain proportion of the total transpiration: 6.3%-33.9% for Cedrus deodara, 12.4%-30.8% for Zelkova serrata, 6.5%-27.6% for Euonymus bungeanus, and 6.0%-21.1% for Metasequoia glyptostroboides across three diameter classes. Due to compounding impact of climatic factors, soil moisture regime, and the tree growth patterns, the diurnal transpiration rate declined since September for all trees. Contrasting characteristics of daily sapflux pattern were found under three typical weather conditions. Sapflux curves of clear sunny days were relatively flat with wide range of peaks, showing an earliest start time of sap\|flow, an latest declining time with the highest daily sap\|flux volume. Sapflux curves of raining days showed steep and narrow peaks accompanied by a latest sap\|flow start time, and earliest declining time along with lowest sap\|flux volume. The performance for cloudy days stood in between. The whole tree water use ranking from high to low during the entire growing season was as follows: Euonymus bungeanus> Zelkova serrata within the 10 cm diameter class, Euonymus bungeanus> Zelkova serrata> Cedrus deodara > Metasequoia glyptostroboides within the 14 cm diameter class, Cedrus deodara >Euonymus bungeanus> Zelkova serrata > Metasequoia glyptostroboides within the 18 cm diameter class, and Cedrus deodara > Metasequoia glyptostroboides within the 24 cm diameter class.