Globally, climate change has become one of the most studied research topics. The Qinghai-Tibet Plateau covers an area of 2.5×10⁶ km², with grassland being the dominant landscape. The plateau represents a typical ecologically fragile zone and has been experiencing rapid warming and precipitation change. Climate change has resulted in massive glacier melting and hydrology cycling change on the plateau. The warming and altered precipitation could profoundly alter soil microbial abundances and community structure, and subsequently influence ecosystem functions and biogeochemical cycling of carbon and nitrogen. In particular, this could influence microbe-driven greenhouse gas emissions in soils, e.g., N₂O. However, responses of soil microbial community structure and functions to the warming and altered precipitation remain largely unexplored on the plateau, especially for the soil microorganisms involved in nitrogen cycling. The present study explored the effects of warming and altered precipitation on the denitrifying bacterial community in alpine meadow soils at Naqu research station on the Qinghai-Tibet Plateau. The effects of short-term (three months)warming (+1℃, +2℃,and +4℃)and precipitation change (50% precipitation decrease and 100% precipitation increase)on denitrifying bacteria (nirS) abundance and community structure were characterized using quantitative polymerase chain reaction (qPCR) and terminal restriction fragment length polymorphism (T-RFLP). The qPCR results showed that temperature increase in all treatments did not significantly affect nirS gene abundances, and both precipitation treatments did not significantly influence nirS gene abundances in the control and 2℃ warming treatments. In contrast, the 4℃ warming coupled with 100% precipitation increase treatments significantly elevated nirS gene abundances, suggesting that the interaction of warming and precipitation increase influenced the gene abundance at higher temperatures. Principal component analysis based on T-RFLP data demonstrated that temperature increase substantially altered the nirS community structure under conditions of no precipitation change and precipitation increase. The nirS community structure of the control and 100% precipitation increase treatments showed similar patterns, while the 50% precipitation decrease treatment demonstrated different community patterns from the above two treatments, suggesting that the nirS community structure was sensitive to precipitation decrease. Canonical correspondence analysis further revealed that the nirS community structure was jointly driven by temperature increase and precipitation change,indicating that the interaction of temperature increase and precipitation contributed to the shift of the nirS community structure.The temperature increase explained the nirScommunity structure variation by 54.2% (P < 0.01),precipitation change was explained by 45.5% (P < 0.05), and the two jointly explained by 19.9%. Our results indicate that short-term warming and precipitation change do not influence nirS gene abundance; however, they do substantially shift the nirS community structure.