Global warming has caused a series of ecological issues in terrestrial ecosystems and the biosphere as a whole; these issues will further aggravate because global average temperatures will continue to increase. Currently, the effects of warming, nitrogen deposition, and forest regeneration on soil nutrients such as N and P have been studied; however, the effects of warming on the coupling between soil N and P in subtropical forests remain unknown. In this study, the influence of short-term warming on the coupling mechanism between soil N and P in Chinese fir (Cunninghamia lanceolata) seedlings in a mid-subtropical plantation was investigated. In the experiment, cables were buried in the soil to increase soil temperature (temperature range (5±0.5)℃). The effects of short-term warming on soil water content, microbial biomass N (MBN), microbial biomass P (MBP), soil N and P, and N and P coupling were studied. The results showed that the effects of short-term warming on total N and total P were not significant. In the first year, temperature increase led to significant increase in effective N, ammonium N, and available P content, and a significant reduction in MBN content. In the second year, with the increase of temperature, the contents of available P, NH₄⁺, and MBP decreased significantly. However, the increase in NH₄⁺/(NO₃^-+NO₂^-) content significantly reduced the MBN/MBP content, and alleviated the limitation of P on microorganisms, but the effects of temperature on total N/P and available N/P were not significant. Correlation analysis showed that the coupling effect was not only influenced by the interaction between N and P, but was also influenced by soil temperature, soil water content, and other factors. These results indicated that short-term warming did not significantly affect soil N-P coupling in the subtropical Chinese fir plantation; however, it increased available N and available P contents by promoting plant growth. Thus, our findings will provide an important theoretical basis for sustainable development and scientific management of subtropical forest ecosystems in the context of future global warming.