The availability of soil nutrients can have significant influence on water quality and wetland productivity. Nitrogen mineralization is the important process transferred from organic nitrogen to plant-available inorganic forms by soil animals and microorganism. Soil nitrogen mineralization processes in coastal wetlands will be greatly impacted by the significant changes of soil water and salt conditions caused by global climate change in the future. However, further studies concerning the effects of water and salt on soil nitrogen mineralization is still needed. The influences of other soil physical–chemical properties and plant community on soil nitrogen mineralization processes are also concluded. The influencing mechanism of soil nitrogen mineralization can be explained using the laboratory incubation, whereas the in situ incubation can contribute to reflecting the real nitrogen mineralization information in the field. The laboratory and in situ incubation methods combined with 15N tracing-isotope technique should be combined and applied to better reflect and explain soil nitrogen mineralization processes. Moreover, the applications of modern molecular biology techniques are also very necessary to quantitatively and accurately study nitrogen mineralization.