Abstract: In this study, a semiopentop artificial climate chamber was used to study the effect of CO₂ enrichment (360 and 540 μmol·mol^-1) and nitrogen addition (0, 150, 300 and 450 kg·hm^-2) on cotton dry matter accumulation and distribution, nitrogen absorption and soil urease activity. The results showed that the dry matter accumulation of bud, stem, leaf and the whole plant increased significantly in the higher CO₂ concentration treatment irrespective of nitrogen level. The dry matter of all the detected parts of plant with 300 kg·hm^-2 nitrogen addition was significantly higher than those with the other nitrogen levels irrespective of CO₂ concentration, indicating reasonable nitrogen fertilization could significantly improve cotton dry matter accumulation. Elevated CO₂ concentration had significant impact on the nitrogen absorption contents of cotton bud and stem. Compared to those under CO₂concentration of 360 μmol·mol^-1, the nitrogen contents of bud and stem both increased significantly under CO₂ concentration of 540 μmol·mol^-1. The nitrogen content of cotton bud in the treatment of 300 kg·hm^-2 nitrogen was the highest among the four nitrogen fertilizer treatments. While the nitrogen contents of cotton stem in the treatments of 150 kg·hm^-2 and 300 kg·hm^-2 nitrogen levels were higher than those in the treatment of 0 kg·hm^-2 and 450 kg·hm^-2 nitrogen levels. The nitrogen content of cotton leaf was significantly influenced by the interaction of CO₂ elevation and N addition as the nitrogen content of leaf increased in the treatments of 0, 150 and 300 kg·hm^-2 nitrogen levels under the CO₂ concentration of 540 μmol·mol^-1. The nitrogen content in cotton root was significantly increased with the increase of nitrogen fertilizer level under elevated CO₂ (540 μmol·mol^-1) treatment. Overall, the cotton nitrogen absorption content under the elevated CO₂ (540 μmol·mol^-1) treatment was higher than that under the ambient CO₂ (360 μmol·mol^-1) treatment. The order of nitrogen accumulation content in organs was bud>leaf>stem >root. Soil urease activity of both layers increased significantly with the elevation of CO₂ concentration in all the nitrogen treatments. Under each CO₂ concentration treatment, the soil urease activity in the upper layer (0-20 cm) increased significantly with nitrogen application, while the urease activity under the application of 300 kg·hm^-2 nitrogen was highest in the lower layer (20-40 cm).  The average soil urease activity in the upper layer (0-20 cm) was significantly higher than that in the lower layer (20-40 cm). This study suggested that the cotton dry matter accumulation and nitrogen absorption content were significantly increased in response to the elevated CO₂ concentration (540 μmol·mol^-1) and higher nitrogen addition (300 kg·hm^-2).