The purpose of this study is to provide the baseline data for conservation and management of the ecosystem of Gyeongju National Park by surveying and analysing the vascular plants distributed in Mt. Manhongbong (522 m). The vascular plants were surveyed form May 2012 to August 2017. The vascular plants on this site was classified as follow. Based on voucher specimens, the vascular plants of this site consisted of 91 families, 292 genera, 397 species, 4 subspecies, 48 varieties and 8 forms. The 2 taxa of threatened species, 11 taxa of rare plants and 14 taxa of Korean endemic plants were investigated. The specific plants by floristic region were totally 39 taxa, which were 3 taxa of grade V, 5 taxa of grade IV, 2 taxa of grade III, 11 taxa of grade II and 18 taxa of grade I. The naturalized plants were identified as 33 taxa and the percentage of naturalized index (NI) was 7.2%, and urbanized index (UI) was 10.3%, respectively. The invasive alien plants were 2 taxa, such as Ambrosia artemisiifolia L. and Aster pilosus Willd.