Soil nitrogen(N)availability is the most limiting factor for plant growth,and increased nitrogen levels heighten exotic species invasiveness.We assessed the effects of interspecific competition and nitrogen fertilization on growth of an invasive plant Aegilops tauschii in pot experiment.And the competition relation was analysed based on the change of morphology,structure,biomass accumulation and allocation under different nitrogen treatment.The monocultures of Aegilops tauschii and wheat exhibited considerable nitrogen acclimation ability with the increase of nitrogen fertilization level,their root/crown ration and leaf area ratio decreased.The increment of biomass growth with nitrogen fertilization level was Aegilops tauschii > wheat.When the amount of nitrogen application was more than 12 g/m2,the root/crown of Aegilops tauschii decreased significantly（P<0.05）,it also shows that the nitrogen responsiveness of Aegilops tauschii is more sensitive than wheat.Most of parameters of phenotypic plasticity of Aegilops tauschii were higher than wheat,indicating that the former was more sensitive to nitrogen application and that this may be partly explained by its superior nitrogen utilization efficiency.In fact,nitrogen addition obviously enhanced the competitive effects of Aegilops tauschii on wheat,particularly interspecific root competition,which was supported by the fact that RCI and AG calculated based on aboveaground,belowground and total biomass were positive,respectively.Our study indicated that nitrogen deposition associated with global change may facilitate the invasion of Aegilops tauschii,and may enhance the vulnerability of native communities to invasion.