Aims: Although studies have investigated how nitrogen (N) and phosphorus (P) deposition alone alter terrestrial ecosystems, the responses of soil microorganisms and their functions to interaction of N and P deposition have not been studied across an elevational gradient in subtropical forests. Methods: By conducting N and P deposition experiments at three elevational levels in subtropical forests, we determined how the responses of soil microorganisms and their functions to N and P deposition differ at low (1300 m), moderate (1800 m), and high (2350 m) elevations. Results: Microbial biomass of most functional groups differed among the three elevations; microbial biomass was lowest at the moderate elevation, and the elevation-induced changes in microbial biomass were positively correlated with soil substrate quality (e.g., soil N/P). After two years of treatment, N deposition had negative effects on microbial biomass and interacted with P deposition at the low elevation, while N or P deposition had positive effects on microbial biomass at the moderate elevation. N deposition decreased SOM-C decomposition at the low (16%) and moderate (8%) elevations; N deposition decreased SOM-N decomposition (10%) at the low elevation but increased SOM-N decomposition (16%) at the moderate elevation. P deposition increased SOM-C decomposition (14%) at the low elevation but decreased SOM-C decomposition (6%) at the high elevation. Conclusions: Our results evidenced that short-term effects of nutrient deposition on soil microorganisms and SOM decomposition were altered by elevational gradient in subtropical forests, suggesting that the effect of nutrient deposition on belowground communities and functions are environmental context-dependent. [ABSTRACT FROM AUTHOR]