Facultative epiphytes is an important component of epiphytic flora of montane forest ecosystems, it refers to a special plant that can both grow in epiphytic and terrestrial habitats. Epiphytic and terrestrial individuals of the same species are different ecotypes that present on different substrates. Studying the stoichiometric characteristics of facultative epiphytes in different habitats is helpful to understand the response of facultative epiphytes to habitat shift and nutrient utilization strategies. Briggsia longifolia is a dominant species of facultative epiphytes in montane moist evergreen broad-leaved forest of the Ailao Mountains, Yunnan Province. This species belongs to Gesneriaceae, which not only has important medicinal, horticultural and ornamental values, but also has high value in the research of taxonomy, evolutionary systematics and phytogeography. In this study, C, N, and P concentrations and their stoichiometric ratios in substrates, leaf and root of B. longifolia among different habitats were analyzed. The results showed that there were differences in the stoichiometric characteristics of the substrate and the different organs of B. longifolia among different habitats. The C, N, P concentrations and C ∶ N, C ∶ P, N ∶ P ratios in the soil of forest floor were lower than those of epiphytic substrate in trunk. The C, N, P stoichiometry in substrate of the trunk base was intermediate the two. The B. longifolia individuals in the epiphytic habitat showed higher N and P concentrations, but lower C ∶ N, C ∶ P and N ∶ P ratios than those in the terrestrial habitat, which indicated that the epiphytic individuals of B. longifolia showed low nutrient use efficiency. In the three habitats, the N concentration and N:P ratio in leaves of B. longifolia were significantly lower than those of the roots, while C ∶ N ratio was higher than that of the roots. The homeostasis values of N, P and N ∶ P in leaves of B. longifolia were stronger than root, and decreased in the order of H_N∶P> H_N> H_P. The weak stoichiometric homeostasis of root indicated that B. longifolia maintained relatively stable metabolic activities of leaf by adjusting the absorption and elemental composition of roots. In conclusion, facultative epiphytes adapt to habitat shifts by adjusting their nutrient uptake and utilization strategies among different habitats and stoichiometric homeostasis between leaves and roots. These findings enrich the theory of plant ecological stoichiometry, and also provide a scientific basis for understanding the formation and maintenance mechanism of biodiversity in montane forest ecosystems, as well as the protection and management of montane forest resources.