Nitrogen (N) and phosphorus (P) are the two most important elements for building plant proteins and genetic material, limiting forest production, and other ecosystem processes, and they profoundly affect litter decomposition. Litter-quality parameters, particularly initial lignin and N contents, ratios of C:N, and lignin:N often correlate strongly with rates of litter mass loss in temperate and boreal forests. Furthermore, soil N availability and N addition also affect litter decomposition. In tropical and subtropical forests, where highly weathered soil is frequently observed, P could be more important than N in inhibiting litter decomposition. However, P has not been considered in most current ecosystem carbon cycling models, but fertilization experiments show different responses of litter decomposition rates to nutrition addition. Synergistic, antagonistic, and neutral effects can be observed. Both the "basic stoichiometric decomposition theory" and "microbial nitrogen mining" hypothesis have been used to explain litter decomposition rate variations with nutrition addition. Regarding rigid C:N:P ratios in microbial decomposers, different nutrition sources could result in altered microbial activity, and limited nutrient supplies could result in restricted litter decomposition. To clearly understand the effects of N and P regulation on decomposition, we need longer decomposition experiment durations, more intensive field and laboratory fertilization experiments, and simultaneously, microbe and enzyme dynamics in the decomposition process should be further investigated.