The genotypic differences in P utilization efficiency, photosynthetic rate, water utilization efficiency and resistance to aging were studied in hydroponics and a field trial. The results showed that chlorophyll content and CO₂ fixation rate of the P-efficient genotypes were 32.0% and 26.0% higher than those of the P-inefficient ones. However, the latter's transpiration rate was 130.0% higher than that of the former's. Subsequently, the water content in rhizospheric soils of the P-efficient ones was 56.5% higher than that of the P-inefficient ones. Malondialdehyde (MDA) content in the leaves of the former was 75.0% lower than that of the latter. This indicated that the P-efficient ones were more resistant to aging than the P-inefficient ones under low P stress. All the genotypes' P utilization efficiencies were raised significantly under the stress condition. The values were increased from 171.5 (full P strength) to 1136.4 for the P-efficient genotypes and from 200.0 to 331.1 kg DM/kg P for the genotypes from the other type. These suggested that light and water utilization efficiencies and resistance to aging related closely to the efficiency of phosphorus utilization by wheat genotypes.