【Objective】Croplands emit greenhouse gases,and improving agronomical management to ameliorate emission has thus been touted as an alternative to mitigate climate change.It has received increased interest over the past decades.In this paper,we review how water-saving irrigations could alter gas emission from cropland.【Method】We analyzed previous research published in the literature with the focus on paddy field and upland.【Result】Compared with flooding irrigation,water-saving irrigation increased CO_2 emissions from paddy field by 20.83%~104.00% with an average of 48.40%;its impact on N_2O emission varied from-41.30% to 3 078.41% with a mean 269.10%.In contrast,water-saving irrigation reduced CH_4 emission by 14.19%~78.92% with an average of 51.66%.In terms of net global warming potential (GWP),water-saving irrigation reduced GWP of paddy field compared to flooding irrigation.In upland,drip irrigation changed the emission of CO_2,N_2O and CH_4 by-31.19%~2.81%,-46.51%~52.56% and-150.00%~43.39%,respectively,compared to flooding irrigation.Since N_2O is a more potent greenhouse gas,drip irrigation still reduces GWP compared to flooding irrigation【.Conclusion】Water-saving irrigation can not only save water but also mitigate greenhouse gas emissions from cropland.