The response of soil gross nitrogen (N) cycling to elevated carbon dioxide (CO2) concentration and temperature has been extensively studied in natural and semi-natural ecosystems. However, how these factors and their interaction affect soil gross N dynamics in agroecosystems, strongly disturbed by human activity, remains largely unknown. Here, a 15N tracer study under aerobic incubation was conducted to quantify soil gross N transformation rates in a paddy feld exposed to elevated CO2 and/or temperature for 9 years in a warming and free air CO2 enrichment experiment. Results show that long-term exposure to elevated CO2 signifcantly inhibited or tended to inhibit gross N mineralization at elevated and ambient temperatures, respectively. The inhibition of soil gross N mineralization by elevating CO2 was aggravated by warming in this paddy feld. The inhibition of gross N mineralization under elevated CO2 could be due to decreased soil pH. Long-term exposure to elevated CO2 also signifcantly reduced gross autotrophic nitrifcation at ambient temperature, probably due to decreased soil pH and gross N mineralization. In contrast, none of the gross N transformation rates were affected by longterm exposure to warming alone. Our study provides strong evidence that long-term dual exposure to elevated CO2 and temperature has a greater negative effect on gross N mineralization rate than the single exposure, potentially resulting in progressive N limitation in this agroecosystem and ultimately increasing demand for N fertilizer.