The effect of root separation on plant nitrogen uptake and nitrate nitrogen residual were investigated through field experiment. The results showed that the nitrogen uptake of faba bean with no root separation were higher than that with root partition, and nitrogen acquisition of grain and straw were increased by 20.10% and 34.43%, yet maize nitrogen uptake with no root separation were little lower than that of with root partition. The nitrate nitrogen accumulation both in soil of faba bean and maize strip with no root partition were higher than that of with root separation in faba bean/maize intercropping. When faba bean intercropped with no maize, faba bean nitrogen uptake with no root separation were significantly higher than that of with root partition, yet there existed no difference between root partition and no root partition for soil nitrogen accumulation in blank soil. And plant nitrogen uptake and nitrate nitrogen accumulation varied little between root separation and no root separation in faba bean/maize intercropping with no faba bean.