| Summary: | Winter irrigation is important for wheat in meeting crop water requirements in spring, but it alters soil moisture dynamics and affects soil N<sub>2</sub>O production and emission. To assess the effects of winter irrigation on soil N<sub>2</sub>O emissions in a winter wheat field, an in situ experiment was conducted from 1 October 2019 to 1 March 2020 with one control treatment (CK) and five levels of winter irrigation quantities (irrigated to 60%, 70%, 80%, 90%, 100% of the soil water holding capacity, namely WHC60–WHC100, respectively). The results showed that winter irrigation had an impact on soil N<sub>2</sub>O emission. The emission peaks were not investigated immediately after winter irrigation, but at two days after, which were increased by 4.3–17.0 μg·m<sup>−2</sup>·h<sup>−1</sup> under WHC60–100 treatments compared to the CK. The cumulative N<sub>2</sub>O emissions after winter irrigation from WHC60–100 were 1.1–3.9 times higher than that of CK, indicating that the cumulative N<sub>2</sub>O emission has an increase trend with the increase of soil water content regulated by irrigations. Pearson correlation analysis showed that the correlation between soil N<sub>2</sub>O flux and soil temperature were moderate with correlation coefficients of about 0.65. While the correlation between soil N<sub>2</sub>O flux and soil water content was poor during the investigate winter season with correlation coefficients ranging between 0.08 and 0.25. Future studies should focus on the general N<sub>2</sub>O emission responses to winter irrigation and environmental factors with the support of experiment data from several winter seasons.
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