Changes in the water consumption characteristics and water use efficiency of poplar, and the influencing factors were investigated, which is significant to the study of the physiology and ecology of poplars, selection of tree species for forestation, and forest ecological engineering. Four treatment groups were set up for pot culture experiments on poplar. Quantitative analysis showed the relationship between the following characteristics of poplars: water consumption, water use efficiency, soil evaporation, plant physiological properties, meteorological environment factors, and soil moisture. The results showed that: (1) the changing curves in the graph on water consumption in the four treatment groups showed single peaks, and that the curves reached their maximums in July and their minimums in February. (2) Water evaporation of soil used for planting poplar accounted for 15.9% of the total water consumption in steady-state situations annually. The background loss accounted for 30.4% of the total water consumption. (3) Water consumption of poplars under surface covering accounted for 53.7% of the total water consumption, and the annual change curves also had single peaks. Furthermore, the total water loss of soil in which poplars were planted was 2.77 times more than that of soil without poplar. The total water evaporation of soil on bare land in which poplars were planted was 7.9% higher than that of soil on bare land without poplar. (4) The average transpiration rates of leaves of poplars under surface covering and on bare land were 30.8 and 9.5 g cm^-2 a^-1, respectively, whereas the average water consumption per gram of biomass was 39.61 g. These results indicate that poplars have a strong water-seeking capacity and high transpiration rate; therefore, planting poplar will cause significant soil moisture loss in afforestation areas, resulting in the desiccation of deep soil and limited regulation of soil water storage in this area.