Based upon the vegetation data of woody plants by plot sampling method in the natural deciduous forest of Mt. Jeombong, the study was carried out to examine importance value, rank abundance curve, and species abundance curve, and comparatively evaluate seven different species diversity indices for Log series, species richness, Margalef index, Shannon–Wiener index, Simpson index, McIntosh index, and Berger–Parker index, according to canopy layer and life form. The minimal area which meant only few more species were increased was 3.48 ha in total. The dominant species of overstory was Quercus mongolica, while Acer pseudo-sieboldianum was the dominant species of both midstory and understory. According to rank abundance curve and species abundance curve, species evenness was low. Log series and the Margalef index had a similar tendency. Also, the Shannon–Wiener index, Simpson index, and McIntosh index showed a similar tendency. However, the Berger–Parker index showed a similar trend with Log series and Margalef index. The dominant species of all growth forms were Quercus mongolica, Acer mandshuricum, and Syringa reticulata var. mandshurica. According to rank abundance curve and species abundance curve, species evenness was also low. Log series and the Margalef index had a similar trend. Also, the Shannon–Wiener index, Simpson index, McIntosh index, and Berger–Parker index showed a similar tendency.