A pot experiment was conducted to investigate the effects of different phosphorus levels on crop biomass，nodule growth，nitrogen fixation and plant nitrogen uptake in maize and soybean intercropping，and preliminarily analyze the relationship between plant nitrogen uptake and biological nitrogen fixation.The results showed that maize and soybean intercropping had significant advantages in nitrogen uptake under different phosphorus levels，and the values of nitrogen absorption equivalent ratio(LERN)ranged from 1.25 to 1.41.Compared with monocropping，the average nitrogen uptake of intercropped maize at three phosphorus levels increased by 30.95%，30.50% and 25.59% at small belling，big belling and booting stages and that of intercropped soybean increased by 42.18%，32.25% and 32.01% at branching，flowering and podding stages，respectively.The nitrogen uptake of intercropped maize and soybean did not reduce in the P50 treatment，compared to the corresponding monocropping in the P100 treatment. At the three growth stages，intercropping and phosphorus fertilizer application significantly increased the nodules number，nodule dry weight and nodule nitrogenase activity on soybean roots，and the reduction of phosphorus fertilizer rate by 50% did not affect the growth and nitrogen fixation of soybean nodules under intercropping.Under the tested conditions，maize and soybean intercropping had the synergistic effects in nitrogen and phosphorus uptake，and reduced the application of phosphorus fertilizer.