Ansan urban nature park is 197.8ha and located in Seodeamun-Gu of Seoul. Flora of Ansan consisted of 141 species, 76 genera, 40 families in woody plants. This study was conducted to analyze the natural environment and establish the park management plan with ecological approach. The result of this study is summarized as follows. 1. The short term plan shall be performed in six vegetation management zones; Robinia pseudoacacia community zone, Sorbus alnifolia community zone, Quercus acutissima community zone, Populus ${ imes}$albagrandulosa community zone, Pinus densiflora community zone, and landscape planting zone. Pinus densiflora and landscape planting zones shall be managed artificially, the others managed with ecological approach. 2. The long term plan shall be performed in four vegetation management zones; Robinia pseudoacacia community zone, Quercus spp. community zone, Pinus densiflora community zone, and landscape planting zone. Pinus densiflora and landscape planting zones shall be managed artificially, the others managed with ecological approach. 3. Because soil of Ansan is acidified and the soil disturbed growth of plants, the improvement of soil is necessary. The fertilization shall be performed in three zones; evergreen confierous tree zone(ex. P. densiflora), Quercus spp. zone, and the other deciduous tree zone(ex. R. pseudoacacia).