This study was carried out to clarify the syntaxonomy of the pine forest in Youngdong region by the phytosociological methods. As a result of the investigation of 62 quadrats, Pinus densiflora forest was classified into four subassociations: Typical subassociation, Quercus mongolica subassociation, Rhododendron mucronulatum subassociation, Rhus chinensis subassociation. Many differences in ecological characteristics such as species composition, stratum structure, vegetation coverage and of diameter at breast height(DBH) of class distribution were found among the communities. Soil properties of the pine forest on the study area was relatively poor compared with other pine forests, especially, soil pH was strongly acidic with 4.87. Soil conditions among the subassociations appeared different. Future succession of pine forest by the similarity index of communities was proposed. Estimated degree of green naturality for Typical subassociation and Q. mongolica subassociation correspond to 7th grade, and R. mucronulatum subassociation, 8-1st grade, and R. chinensis subassociation, 8-2nd grade.