Nitrogen (N) mineralization is an important component of nutrient cycling in wetland ecosystems, and effects of nitrogen input and temperature change on nitrogen mineralization of soils are complex. To explore the effects of temperature and N import on N mineralization characteristics of soils with different N treatments, the topsoil (0-10 cm) with different substrate qualities (S-N0, S-N1, S-N2 and S-N3) were sampled at the end of the growing season from different N input plots (N0: 0 g N m^-2 a^-1; N1: 9.0 g N m^-2 a^-1; N2: 12.0 g N m^-2 a^-1; N3: 18.0 g N m^-2 a^-1) in Suaeda salsa marsh of the Yellow River estuary, and the incubation experiment was carried out. Results showed that, under different incubation temperatures, the cumulative mineralized N of the four soils increased rapidly at initial stage (0-14 days), after that decreased suddenly at middle stage (14-42 days), then tended toward stability at final stage (42-84 days), and the values in incubation period generally showed S-N3 > S-N0 > S-N2 > S-N1 (P > 0.05). At the end of incubation experiment, the cumulativly mineralized N of the four soils were significantly different at 20 ℃ and 25 ℃ (P < 0.01 or P < 0.05), and S-N2 showed the strongest mineralization ability. N input generally decreased the sensitivity of N mineralization to temperature (Q₁₀), thereinto. S-N2 showed the lowest Q₁₀ and it was more favorable for continuous N supply. The mineralization rates and cumulative mineralization N of the four soils were closely related to incubation temperatures and substrate qualities of soils, while within a certain range, higher temperatures and lower C/N were more favorable for the process of N mineralization. This study found that, as N loading and temperature in the Yellow River estuary increased continuously in future, the alterations of soil N nutrient and temperature would greatly affect the N supply capacity of S. salsa soils, and the soils with N2 input would maintain sustainable and stable N supply capacity.