This study explored the key factors that lead to differences in water consumption among different populations with different genotypes, to evaluate genotype-specific water consumption traits and select ideal varieties with low water requirements. Fifteen near-isogenic lines (NILs), along with their donor parent Jing 411 and recurrent parent Jinmai 47, were used as materials in this experiment. The materials tested have significantly different water consumptions, but there are no significant differences in their yields under water deficit conditions. Automatic rain-shelter and rain-proof pools that can prevent water seepage were used for the simulated water deficit treatment. The soil water content of all the genotypes were monitored over the whole experimental period and the total water consumption was calculated using the water balance equation. Grain yield was measured after harvest and then the water use efficiency (WUE) was calculated. The canopy-air temperature difference (CTD), leaf transpiration rate, and stomatal conductance were also monitored at the jointing-booting, heading-flowering, and grain-filling stages. The results indicated that the 15 NILs, along with their parents, had significantly different CTDs during all three growth periods. Analysis of variance for the CTD differences indicated that genotype, and growth and development year significantly affected CTD, but there was an interaction between the two factors only at the heading-flowering stage (P=0.0002). There were significant differences in water consumption among the 15 NILs and their parents. However, there were no significant differences in yield. The differences in water assumption meant that there were significant differences in WUE among some genotypes. The CTDs at all three growth and development stages negatively correlated with water consumption. The R² value was the highest at the heading-flowering stage, and was 0.7042 and 0.6095 during 2012-2013 and 2016-2017, respectively. The correlations between leaf transpiration rate, and stomatal conductance and water consumption were very weak among the 15 NILs and their parents. The correlations were not significant for any of the three growth and development stages. The results for the near-isogenic lines tentatively indicate that under water deficit conditions, the canopy structure traits, rather than leaf gas exchange properties such as leaf transpiration rate and stomatal conductance, significantly affect population-specific water consumption. The results also show that establishing a suitable population canopy structure increases yields and can control water consumption, which leads to an improvement in WUE.