N₂O emissions from paddy soils with various water contents incubated at 30 C were measured. During the 39 days' incubation, soil with water content up to its field capacity had the highest N₂O emission. When soil water content was above the field capacity, dentrification was the dominant process for N₂O formation. And when soil water content was below the field capacity, there was only a small amount of N₂O emission, though the nitrification was most significant. In a pot experiment,N₂O and CH₄ fluxes from paddy soils under normal water management, continuous flooding and moist irrigation were measured over the rice-growing season. There was little N₂O emission from paddy soil under continuous flooding. Unfortunately, the emission of CH₄,another important greenhouse gas, dramatically increased. In contrast, there was no significant CH₄ emission from paddy soil under moist irrigation whereas its N₂O emission was much higher than other treatments.