‘Functional traits’’ capture fundamental tradeoffs that determine species’ ecological roles. In Yushan National Park, establishing morpho-physiophenological traits which impact fitness indirectly via their effects on growth, reproduction and survival, the three components of individual performance can become the foundation of ecological forensics. This preliminary study will initiate leaf functional traits about Ericaceae in Nanhsi area. Carrying on the standard protocol of leaf functional traits can input, provide and accumulate long-term ecological forensics data and renewal conservation information for National Park’s management and long-term ecological research. Sampling area from 1800m to 3900m above sea level in Nanhsi area, 1210 leaf samples were collected from 242 shoots for 178 individuals of 9 species and 5 genera in Ericaceae. Laminar density (LD) of the sampling rhododendrons was usually low toward the high altitude. Leaf dry matter content (LDMA) of most rhododendrons was between 0.3 and 0.5. Only those LDMA values of Gaultheria itoana Hayata and Vaccinium randaiense Hayata increased along their enlarging leaf areas. Leaf thickness inclined along the LDMA but declined in specific leaf area (SLA), except Lyonia ovalifolia (Wall.) Drude. The smallest closed areoles in leaf vasculature occurred in Rhododendron morii Hayata and the largest ones occurred in R. rubropilosum Hayata. Short terminal veins with obvious bundle sheath of R. morii displayed probably the C4 photosynthetic pathway. On the contrary, the bundle sheath of R. rubropilosum was not dominant. Results are the first time to show the leaf functional traits applied to the same species rhododendrons in different habitats, sun- or shade- leaves of the same individuals and the adaptation to special montane ecosystem. It would carry on the important mission of long-term monitoring and also shows the efforts and contribution of Yushan National Park Headquarter in conservation.