Background <p>Litter decomposition is critical for managing soils as carbon sinks and predicting soil organic matter dynamics under climate change. Anthropogenically-induced nitrogen and phosphorus enrichment has altered the role and diversity of soil biota, thereby profoundly regulating litter decomposition process. However, the biochemical decomposition pathways involved in litter decomposition in response to nitrogen and phosphorus enrichment remain unclear.</p> Scope <p>Here, we review how soil biota (microorganisms and fauna) and extracellular enzymes influence the biochemical decomposition of litter and discuss the effects of nitrogen and phosphorus addition on this process along with associated pathways and mechanisms.</p> Conclusions <p>The results showed that the effects of nitrogen and phosphorus addition on microbial community structure depend on their life-history strategies as well as the amount and ratio of nutrients inputs. Nitrogen and phosphorus addition can also affect soil fauna diversity mainly by changing chemical stress, microclimate, and resources availability. However, how soil fauna regulate microbial communities during litter decomposition under nitrogen and phosphorus addition needs more studies. Nitrogen and phosphorus addition differentially affect extracellular enzyme activities, which may be related to the resource allocation strategy of soil biota. The effect of nitrogen and phosphorus co-addition is generally more significant than that of their single addition due to the synergistic effects. Overall, this review provides new insights into the understanding of soil biota roles and their mediated responses of litter biochemical decomposition pathways to nitrogen and phosphorus enrichment, which is expected to optimize plant and soil nutrient management practices in sustainable ecosystems under climate change.</p>