Abstract: In order to reveal the effects of irrigation water amount on soil CO₂,N₂ O emissions and spring maize growth under groundwater and brackish water irrigation,two kinds of irrigation water salinity（1.1 g/L and 5.0 g/L） and three kinds of irrigation water amounts（210 mm,255 mm and 300 mm）were set up in Hetao Irrigation District from April to September,2019.The results showed that compared with groundwater（1.1 g/L） irrigation,soil N20 emissions were increased by 19.86%～44.21% under brackish water（5.0 g/L） irrigation,but irrigation water salinity did not affect soil CO₂ emissions and global warming potential（GWP）.Under the same irrigation water salinity conditions,cumulative CO₂ emissions,cumulative N₂ O emissions and GWP were the largest when the irrigation water amount was300 mm,and the cumulative CO₂ emissions,cumulative N20 emissions and GWP were not significantly affected by the irrigation water amount of 210 mm and 255 mm.The results of correlation analysis showed that soil moisture and inorganic nitrogen content were important factors affecting soil CO₂ and N₂ O emissions,and irrigation water salinity promoted soil N20 emissions by promoting soil nitrification.The yield of spring maize under brackish water（5.0 g/L） irrigation was 30.88%～37.32% lower than that under groundwater（1.1 g/L） irrigation.The yield of spring maize was increased with the increase of irrigation water amount,but there was no significant difference under the irrigation water amount of255 mm and 300 mm.Under the condition of groundwater（1.1 g/L） and brackish water（5.0 g/L）irrigation,when the irrigation water amount was 255 mm,the soil salt accumulation was smaller,while the higher spring maize yield was obtained,and the cumulative CO₂ and N₂ O emissions and GWP were relatively small,which was the suitable irrigation quota for Hetao Irrigation District.