The effect of density-dependent regulation on soil N₂O flux in Ligustrum lucidum plantation in Jiangdu district of Yangzhou was studied. The results showed that the fluxes under the three densities had high values in autumn and spring and low values in winter. In autumn, the average of N₂O flux showed: 4225 tree/hm² (9.985 μg·m^-2·h^-1)＞1050 tree/hm²(8.195 μg·m^-2·h^-1)＞2275 tree/hm² (6.971 μg·m^-2·h^-1). In winter, the N₂O flux significantly decreased in which both 4225 tree/hm² (-10.355 μg·m^-2·h^-1) and 2275 tree/hm² (-2.716 μg·m^-2·h^-1) were significantly lower than 1050 tree/hm² (2.629 μg·m^-2·h^-1). The N₂O flux in the plot with a density of 2275 tree/hm² (7.513 μg·m^-2·h^-1) was lower than that in other two plots and the difference was highly significant (P＜0.01). In summer, the N₂O fluxes in three plantation densities were as follows: 4225 tree/hm², 3.201μg·m^-2·h^-1; 2275 tree/hm², 7.658 μg·m^-2·h^-1; and 1050 tree/hm², 6.804 μg·m^-2·h^-1. The N₂O flux had a significant positive relationship with soil temperature (P＜0.01), while it had an extremely negative correlation with NH₄⁺-N and NO₃^--N content (P＜0.01). A highly significant correlation between N₂O flux and soil nitrogen mineralization (P＜0.01) was also observed. It is suggested that density-dependent regulation would affect soil factors and have significant influence on N₂O emission.