The forest vegetation of Mt. Nam Nature Park was investigated according to the phytosociological method. The vegetation in this study area was classified into 5 communities Quercus mongolica (Acer pseudo-sieboldianum subcommunity, Prunus sargentii subcommunity), P. sargentii, Pinus densiflora (Q. mongolica subcommunity, Stephanandra incisa subcommunity) and 5 afforestations Robinia pseudo-acacia, Populus tomentoglandulosa, P. koraiensis, P. rigida, Metasequoia glyptostroboides. Generally, were P. densiflora forest at the Southern slope and Q. mongolica forest at Northern slope dominant species from the top zone standing in Namsan tower. The dominance sequences on each stratum determined by the R-NCD (Relative net Contribution Degree) showed Q. mongolica and P. densiflora in tree-1 layer, Styrax japonica and Corbus alnifolia in tree-2 layer, S. incisa, S. japonica and rhododendron schlipenbachii in shrub layer, and Oplismenus undulatifolius, Eupatorium rugosum, Parthenocissus tricuspidata and Disporum smilacinum in herb layer. The soil was analyzed to investigate the soil conditions and fertility. The pHs of soil collected in each sites appeared strongly acidic with the range of 4.34 to 5.01 each community and especially, was the lowest value 4.34 in P. rigida afforestation. And Q. mongolica-P. sargentii subcommunity was distributed at the area with relative mesic conditions and high organic matters. Nitrogen was highest at P. sargentii community, phosphate at P. densiflora-S. incisa subcommunity, calcium, potasium and magnesium of exchangeble cation at R. pseudo-acacia afforestation. Especially, the level of calcium in R. pseudo-acacia afforestation, P. koraiensis afforestation and P. densiflora community was shown the highest (0.38-1.48 mg/100g) compared to other communities, because of the influence of lime fertilization used to improve acidic soil.