The impacts of climate change on the carbon cycle of wetland ecosystems have received considerable attention worldwide. However, the effects of global warming on the decomposition of litter from wetland plants, which is essential for anticipating the effects of climate change on the carbon source / sink function of wetlands, remains poorly understood. In the present study, experimentally examined the influence of atmospheric warming on plant biomass reduction at atmosphere, water, and soil⁃water interfaces, using open⁃top chambers that generated different warming conditions ((2.0±0.5) °C and (3. 5 ± 0. 5 ) °C) and four dominant lakeside plants ( Zizania caduciflora, Scirpus tabernaemontani, Sparganium stoloniferum, and Hippuris vulgaris) from the Napahai wetland, which is located on the Northwestern Yunnan plateau. The results revealed that (1) experimental warming promoted the mass decay of all four plant species at all interfaces, and the decay rate at the water interface was highest, followed by that at the soil⁃water interfaces and atmosphere, respectively. (2) htt p:/ /w ww .ec olo gic a.c n http: / / www.ecologica.cn The decomposition rates were correlated with the initial C / N ratio of plant litters, regardless of the experimental warming conditions, and the decay of biomass from plants with lower C / N ratios was more sensitive to warming than those with higher ratios. (3) Overall, litter decomposition was affected more by the initial C / N ratio than by the warming treatments. However, the present study still suggests that global warming could promote the decomposition of plant matter in wetland ecosystems in Northwestern Yunnan, with considerable consequences for the carbon cycle and ecological functioning of wetland ecosystems. Accordingly, studies should continue to examine the mechanisms underlying the effects of atmospheric warming on litter decomposition.