This study surveyed mushrooms as part of the Hallasan Natural Reserve Basic Academic Survey, which was conducted for the purposes of securing basic data on the Hallasan Mountain Natural Reserve; our study targeted the area between Seongpanak Trail and Donnaeko Trail from April to October 2018. A total of 392 species from 184 genera in 65 families were investigated. Among them, 187 mushrooms were wood-decaying species. The greatest diversity in mushroom species was recorded in July (206 species) at an altitude of 600-800 m above sea level. Among the mushrooms investigated, five were climate-sensitive biological indicator species and two were potential candidates for that classification. Of these, 163 species were biological resources that require approval for overseas export.