In recent years, nitrogen deposition has increased globally because of the worldwide combustion of fossil fuels, industrial development, and production and use of artificial nitrogen fertilizers. Nitrogen deposition can not only promote organic mineralization and increase nutrient availability, but can also cause soil acidification and nitrate leaching, once nitrogen input overcomes the accumulation ability of plants and soil microorganisms in ecosystems (i.e., nitrogen saturation). The objective of this study was to investigate the responses of temperature sensitivities (Q₁₀) of soil organic carbon mineralization rates (C_min) and enzyme kinetic parameters to nitrogen additions in a subtropical forest. We selected soil samples from a long-term field nitrogen addition experiment conducted in the subtropical soil of Chinese fir plantations. The three nitrogen addition treatments, i.e., control (N0), low nitrogen (N1:50 kg N hm^-2 a^-1), and high nitrogen (N2:100 kg N hm^-2 a^-1), were established in 2011 with three 20 m×20 m replicate plots for each treatment. The soil samples were incubated at 10-40℃ in the laboratory to measure Q₁₀ of C_min and β-1,4-glucosidase (βG) kinetic parameters. The results showed that (1) the nitrogen additions increased C_min, which varied as N2 > N1 > N0, but the differences between the Q₁₀ (C_min) values were not significant. (2) The nitrogen additions increased the maximum rates of velocity (V_max) and catalytic efficiencies (V_max/K_m) as N2 > N1 > N0; this was consistent with the soil C_min, but the nitrogen additions had no significant effect on the half-saturation constant (K_m). The Q₁₀ (V_max) and Q₁₀ (K_m) values varied as N2 > N1 > N0, but the Q₁₀ (V_max/K_m) value showed no significant differences between the N addition treatments. (3) At 30℃, the correlation analyses showed that the C_min values were positively correlated with the total phosphorus (TP), nitrate nitrogen (NO₃^--N), and available phosphorus (aP) contents and V_max. Furthermore, the V_max values were positively correlated with the TP and NO₃^--N contents, and were negatively correlated with the pH values. Moreover, the K_m values were negatively correlated with the total nitrogen (TN) contents, and the V_max/K_m values were negatively correlated with the pH values and were positively correlated with the TP contents. Under 30-40℃ incubation, the Q₁₀ (V_max) values were negatively correlated with the pH values, while the Q₁₀ (V_max/K_m) values were negatively correlated with the TN contents. This study provides the key parameters for modeling the responses of soil carbon cycling biochemical process to increasing temperature under increased nitrogen deposition conditions.