This study was carried out to examine the flora and vegetation structure in Gayasan (Mt.) National Park, to analyze environmental and growth characteristics in Pedicularis hallaisanenesis habitats, and to investigate the possibility of establishing a reproductive system for the seed of Pedicularis hallaisanensis, which is in the endangered wild species II class in Korea. Twenty-four plots (400㎡) in Geuknakgol and 33 plots in Younggigol were set up to understand the flora and vegetation structure of Gayasan National Park(Yonggigol). Three groups of Pinus densiflora-Acer pseudosieboldianum group, Pinus koraiensis-Quercus mongolica group, Pinus densiflora-Quercus mongolica group community were classified by cluster analysis in Geuknakgol. The Species diversity (H´) of investigated groups were ranged from 0.9542 to 1.2553. Two groups of Quercus mongolica-Pinus densiflora group, Pinus densiflora-Quercus mongolica group community were classified by cluster analysis in Yonggigol. The Species diversity (H´) of investigated groups were ranged from 0.9542 to 1.1461. The flora in Gayasan National Park was classified to as; 483 taxa; 96 families, 283 genus, 421 species, 4 subspecies, 47 varieties and 11 forma. Korea endemic plants were appeared Abies koreana, Aconitum austrokoreense, Aconitum pseudolaeve etc. 22 taxa. The naturalized plants were appeared Rumex obtusifolius, Veronica persica, Ambrosia artemisiifolia etc. 21 taxa, The rate of naturalization was 4.3%. P. hallaisanensis habitats were located on the slope of southwest at an elevation of 1,400m in Gayasan (Mt.) and on the slope of southeast at an elevation of 1,500m in Hallasan (Mt) habitats. Habitats were also found on the grassland without upper vegetation. Soil pH and soil organic matter in the habitats were 4.9-6.5 and 4.4-8.1%, respectively. A total of 55 vascular plants taxa in both habitats were 25 in Gayasan (Mt.) and 37 in Hallasan (Mt.). The seed of P. hallaisanensis is egg-shaped, and the seed coat is dark brown. The embryo was identified as a dwarf type by the seed section. The seed length was 0.47 ± 0.07 mm, width 0.16 ± 0.006mm, and thickness 0.12 ± 0.01mm. The weight of one seed was 0.0003 ± 0.0001mg, and 1000 seeds weighed 4.59 ± 0.02mg. The degree of seed viability was 75.33% by the tetrazolium (TZ) assay. The highest germination rate of P. hallaisanensis seed was 71% after 4 weeks of storage at 4°C. However, the germination rate tended to decrease gradually over a longer storage period. The germination rates after 6 or 8 weeks of storage at 4°C were 64% and 60%, respectively. We used two host plants, Artemisia princeps and Dendranthema zawadskii, to determine the effect of host plants on P. hallaisanensis seed germination. The germination of P. hallaisanensis mixed with A. princeps or D. zawadskii started at 53.5 and 62.5 days after sowing, respectively. We did not find any germination 164 days postsowing with both host plants. When A. princeps and D. zawadskii were used as host plants for P. hallaisanensis seed germination, P. hallaisanensis seed germination rates were 45.5% and 19.5%, respectively. The average time to germination was 70.2 days for A. princeps, and 46.8 days for D. zawadskii. The results indicate that current status of P. hallaisanensis habitats were very vulnerable with the pressure of the vegetation constantly threatening the species’ survival. Thus, specific conservation plans including diverse factors as light intensity, temperature and genetic analysis are needed to protect natural habitats and to establish reproduction systems in P. hallaisanensis.