A pot experiment was established to study the seasonal changes in nitrogen(N)uptake and utilization efficiencies of different genotypic variations of wheat.Six wheat cultivars(LM1，ZM9023，YM18，XY22，XY6 and XY107)were cultured in soils with two N fertilizer treatments，low N and high N.Wheat shoot and root samples were taken at the tillering，jointing，heading，filling and maturity stages.Results indicated that the cultivars LM1 and XY107 had the highest N uptake efficiency(NUpE)in the low N treatment(LN)and high N treatment(HN)，respectively，whereas YM18 and LM1 had the highest N utilization efficiency(NUtE)in LN and HN，respectively.The cultivar XY6 had the lowest NUpE and NUtE in both N treatments.The differences of the cultivars in NUpEs and NUtEs mainly occurred after filling stage.The cultivars with higher NUtEs also had higher glutamine synthetase activities in LN.However，the root biomasses and activities were not significantly different among the cultivars that differ in NUpEs.