The research has analysed the targeted land situation, the composition of species, legally controlled plants, vegetation distribution, dominance, species diversity, and the similarity to evaluate the plant characterization of the eco forest in Jangsan, Busan. The results of the research is as following. The number of the plants that belongs to the area is 63 families, 126 genuses, and 163 species. Among them the fern plants : 4 families, 5 genuses, 5 species, and the egg species : 5 families, 8 species, 10 species, and angiospermae : 54 families, 113 genuses, 148 species have been checked. Monocotyledoneae of angiospermae : 7 families, 20 genuses, 22 species (13.5%) and dicotyledoneae : 47 families, 93 genuses, 126 species (77.3%) have been totally checked. The endangered wildlife species by the standard of the Ministry of Environment and the rare plants by the standard of IUCN evaluation realesed by the Bureau of Forest and National Plant Institution has never been checked but one species of Weigela subsessilis has been checked as an approving plant in being delivered abroad, the 8 imported plant by the standard of National Plant Institution checked, some disturbing ecosystem plants released by the Ministry of Environment (2009) not emerged. The succession into the oak trees is occurring to the biodiversity of the researched area, the number of species and their species diversity.