Global environmental change regulates forest litter decomposition by changing the quality and yield of litters, soil biotic and abiotic factors, which may consequently induce a large change in nutrient cycling and energy flow in forest ecosystems. Under current and future conditions, terrestrial ecosystems will be experienced to concurrently multiple global change drivers, which pose challenges for understanding and projecting terrestrial carbon-climate feedbacks. This article presented a comprehensive review and analysis of the responses of forest litter decomposition to two naturally co-occurring anthropogenic global change drivers, precipitation regime alteration and atmospheric nitrogen (N) deposition. We found that environmental changes could affect litter decomposition via direct and indirect pathways. A changing precipitation regime, such as decreased precipitation, may indirectly suppress litter decomposition by altering initial litter quality, while N enrichment usually stimulates litter decomposition by increasing litter initial quality. Precipitation regime alteration can also influence microbial catabolism processes by changing soil moisture and oxygen diffusion, and/or alter the processes of leaching, while the addition of N stimulates or inhibits the processes of microbial catabolism by directly changing the external nitrogen availability. Therefore, we infer that the interaction of precipitation regime alteration and N deposition may have multiplicative, synergistic or antagonistic effects. Although many previous studies contributed to understand how single global change factor affect litter decomposition, there have been few studies aimed at understanding how precipitation regime alteration and atmospheric nitrogen deposition interactively affect litter decomposition in forest ecosystems. Moreover, most of the existing studies focused on the characterization and quantification of environmental factors on the leaf litter decomposition rather than root decomposition. We further developed a conceptual framework of the above- and below-ground litter decomposition under the context of precipitation regime alteration and atmospheric N deposition and also took soil properties, litter quality, and microbial community structure and function into consideration. We finally proposed that future studies on forest litter decomposition should focus on: 1) explain the mechanisms driving the above- and below-ground litter decomposition; 2) explore the effects of precipitation regime alteration and N addition, and their interaction on the forest litter decomposition rate and nutrient release; and 3) elucidate how precipitation regime alteration and N addition, and their interaction influence microbial community structure and function. These studies will improve our understanding of the mechanisms of above- and below-ground litter decomposition in response to global changes, and the maintenance mechanisms of the soil "carbon pool" under global changes condition.