In order to provide a support basis for agricultural greenhouse gas mitigation under future climate change，the effect of elevated atmospheric CO₂ concentration on greenhouse gas emissions from the typical summer maize field in North China was studied.This experiment was carried out in a typical maize field based on the platform of free air carbon dioxide enrichment in North China，which has been in run for 10 years.In 2017，two treatments were set up，including ambient concentration of CO₂ (aCO₂，400 μmol·mol-1)and high concentration of CO₂ (eCO₂，550 μmol·mol-1)..In 2018，four treatments were set up，including two CO₂ concentrations at two different nitrogen levels (LN at N 90 kg·hm-2 and HN at N 180 kg·hm-2，briefed as aCO₂-LN，aCO₂-HN，eCO₂-LN，eCO₂-HN).The characteristics of soil N2O and CO₂ emission fluxes and the potential of nitrification and denitrification under aCO₂ and eCO₂ conditions were measured in the study.Results showed that under the condition of eCO₂，the emissions of N2O and CO₂ were significantly increased by 45.5%～65.9% and 16.7%～19.2%，respectively，in the summer maize growth period.The increase in N2O emissions mainly occurred after fertilization and irrigation，and the increase in CO₂ emissions mainly occurred in the vegetative growth of summer maize. Both the processes of soil nitrification and denitrification may contributed to the N2O emissions，with the potential increase by 36.4% and 59.0% under eCO₂ concentration，respectively.Under eCO₂，mitigation practices on N2O emission should be adopted according to the N2O production mechanisms in the future.