To investigate the effects of elevated CO₂ and temperature on plant biomass production and N uptake, Chinese cabbages were grown at two rates of N (350 and 700 mg kg^-1) under contrasting atmospheric CO₂ (360 and 650 µmol mol^-1) in combination with current ambient or elevated (ambient +5°C) temperature for 70 days. Temperature, CO₂, and N rate significantly affected dry matter yield of Chinese cabbage. Elevated CO₂ suppressed dry-mass accumulation of the plants receiving N at 350 mg kg^-1 irrespective of temperature, but the degree of suppression was significantly reduced for the plants receiving N at 700 mg kg^-1 only when coupled with elevated temperature. Temperature and CO₂ significantly affected N content of Chinese cabbages, while N rate did not. Irrespective of temperature and CO₂ levels, N uptake efficiency was reduced with increasing N rates. However, N uptake efficiency of the plants receiving high N rates grown at elevated-temperature regimes increased at elevated CO₂ levels whereas that of their counterparts grown at ambient-temperature regimes decreased, suggesting that the N rate of 700 mg kg^-1 would be insufficient to ensure optimum growth of Chinese cabbages under elevated temperature and CO₂. Our results suggest that an alternative N fertilization for Chinese cabbages should be tested if a doubling of atmospheric CO₂ level leads to elevated temperatures.