Vegetation structure of Seokseong fortress in Buyeo-Gun was investigated to suggest a desirable management proposal. Communities by phytosociological method were classified into Pinus rigida-Pinus densiflora community and Quercus variabilis community. The importance value of Pinus rigida, Pinus densiflora, Quercus variabilis, Pinus thunbergii, and Quercus acutissima were 127.06, 70.29, 69.63, 12.39 and 8.57. According to breast diameter analysis results, it is expected that the importance value of Pinus rigida, Pinus densiflora, and Quercus variabilis will be continuously increased. It should be prepared that vegetation management plan over the castle wall should be considered before the repair or restoration of castle wall. Vegetation management around castle wall should be carried out according to the mid or long-term plan and it would be needed to consider the gradual changes from planted Pinus rigida to the historical vegetation of Pinus densiflora.