Abstract:The aim was to understand the leaf function of ferns grown under different habitats. The leaf characters of six ferns, such as specific leaf area, gas exchange rates, leaf nutrients, construction cost, and carbon isotope ratio, in monsoon evergreen broad-leaved forest in Dinghushan Mountain were measured, and their adaption to environment were studied. The results showed that two epiphytic ferns (Microsorum fortune and Pseudodrynaria coronans) had low specific leaf area (SLA) and photosynthetic rates (Aarea), but high leaf construction cost (CCarea) and carbon isotope ratio (δ13C). In contrast, two terrestrial ferns (Adiantum flabellulatum and Alsophila spinulosa) showed high Aarea and relative low δ13C. Hicriopteris chinensis growing on bared rocks at forest edge had the lowest leaf phosphorus contents, and the highest photosynthetic phosphorus use efficiency among the six fern species, while Selaginella delicatula growing in streamside had the highest SLA, and the lowest CCarea and δ13C. Therefore, it was suggested that there were close relationship between leaf traits of ferns and environment. In addition, because of high energy investment and low photosynthetic rate, epiphytic ferns have low adaption ability to environment, their survive might be under great pressure.