Atmospheric CO₂ levels are expected to exceed 700 L mol mol^-1 by the end of 21st century.Therefore the influence of increased CO₂ concentration on crop plants is of major concern.This study is an analysis of growth of and N and P concentrations in winter wheat(Triticum aestivum L.cv.Xinong 8727) grown under two levels of atmospheric CO₂ concentration(350 L mol mol^-1 and 700 Lmol mol^-1)and of nitrogen fert ilizer(45 kg hm^-2 and 90 kg hm^-2).Results showed that plant height,leaf area index (LAI)and net assimilation rate(NAR)increased,while leaf area ratio(LAR)reduced and specific leaf weight(SLW)remained unchanged under the high atmospheric CO₂ concentration.The influence of CO₂ enrichment on relative growth rate(RGR)was dependent on N level.Higher CO₂ concentration increased RGR significantly in the high N treatment,but did not increase in the low N treatment.Tasseling of winter wheat advanced by 7~8 days and masses of leaf sheaths,stalks and shoots also increased with CO₂ concentration increasing.Higher CO₂ decreased N and P concentrations in leaves,leaf sheaths and stalks, however it increased N uptake by winter wheat slightly.Higher CO₂ concentration increased use efficiencies of N and P(NUE and PUE),but did not affect relative nitrogen and phosphorus accumulation rates (RNAR and RPAR).Dilution of N and P due to increased dry mass and the enhancement of the use efficiencies of N and P can explain the decline in plant N content in the present experiment.