【Objective】This study was conducted to examine the effects of elevated atmospheric carbon dioxide (CO_2) concentration and temperature on nitrous oxide (N_2O) emissions from annual rice-wheat rotation systems, so as to gain an insight into N_2O fluxes response to climate change.【Method】An in-situ field experiment was established in annual rice-winter wheat rotation systems under a T-FACE platform, consisting of four treatments under different CO_2 concentration and temperature levels (ambient CO_2 + ambient temperature, ambient; 500 mumol·mol~(-1) CO_2 + ambient temperature, C; ambient CO_2 + temperature increased by 2℃, T; 500 mumol·mol~(-1) CO_2 + temperature increased by 2℃, C+T) during 2012-2015. The fluxes of N_2O from rice-wheat rotation fields were measured using static opaque chamber-gas chromatograph method.【Result】(1) On an average of two rice-growing seasons, elevated atmospheric CO_2 concentration significantly increased the biomass and yield of rice by 9.7% and 5.6%, respectively, and those increments of wheat were 11.3% and 5.7% over the three wheat-growing seasons(P<0.05), respectively; Elevated temperature significantly reduced the biomass and yield of rice by 21.1% and 31.6%, and those reductions of wheat were 18.0% and 17.7%, respectively; The combination of elevated CO_2 and temperature significantly reduced the biomass and yield of rice by 13.5%(P<0.05)and 26.0%, and those reductions of wheat were 8.7% and 10.3%(P<0.05), respectively. (2) Either elevated CO_2 concentration or temperature did not affect the seasonal patterns of N_2O emission from rice-wheat rotation system. Elevated CO_2 concentration increased N_2O emissions in rice and wheat season by 15.2% and 39.9%, respectively. Elevated temperature did not affect N_2O emissions in rice season, but it significantly increased N_2O emissions in wheat season by 20.5% (P<0.05). Despite of a considerable interannual variability, N_2O emissions tended to be increased by the combined effect of elevated CO_2 concentration and temperature in rice season; the emissions of N_2O in wheat season were significantly increased by 46.0% under the condition of C+T treatment. (3) The cumulative N_2O emissions in wheat were positively correlated with belowground biomass of wheat and DeltaSOC. (4) Elevated atmospheric CO_2 concentration, elevated temperature and their combination increased GHGI of rice-wheat rotation field by 29.1%, 66.3% and 81.8%, respectively.【Conclusion】All of these results showed that both elevated CO_2 concentration and temperature had a strong impact on the emission of N_2O in rice-wheat rotation field. Elevated CO_2 concentration significantly increased the emission of N_2O in both rice and wheat seasons; Elevated temperature significantly increased N_2O emission in wheat season, but no significant change was observed in rice season. Elevated CO_2 concentration increased N_2O-derived GHGI from rice-wheat rotation field, but it was not significantly different; Elevated temperature and the interactive between elevated CO_2 concentration and temperature significantly increased GHGI. The effects of different applied treatments on N_2O-derived GHGI from rice-wheat rotation field from high to low in order were: C+T>T>C. It was suggested from this study that to ensure present crop supply level under the condition of high atmospheric CO_2 concentration and temperature would likely to exacerbate climate change by increasing N_2O emission.