This study aims to investigate the characteristics of the vegetation structure in the sectin stretching between the Jilmoi wetlands and the Donghae Observatory and to set the criteria for the basic data for a management plan including restoration afterwards. 12 plots(10 m×40 m, 20 m×20 m) were set up to analyse the vegetation structure. The analysis of the classification by TWINSPAN and ordination by DCA, importance percentage and property, distribution of diameter of breast height, growth increments of major woody species, species diversity and the physicochemical properties of soil were all analyzed. Vegetation classes were divided into 3 communities, which are community Ⅰ(Pinus densiflora community), community Ⅱ(Quercus mongolica community) and community Ⅲ(Quercus mongolica-Tilia amurensis community). The P. densiflora community declined when competing with Q. mongolica and Fraxinus rhynchophylla and Q. mongolica competed with T. amurensis on an understory layer in Q. mongolica community. Q. mongolica competed with T. amurensis on both canopy and understory layers in Q. mongolica-T. amurensis community. P. densiflora declined and it was assumed to succeed to F. rhynchophylla or T. amurensis through Q. mongolica based on the importance percentage and distribution of the diameter of the breast height of small and middle sized trees. The age of P. densiflora was between 47 to 51 years old and Q. mongolica was 61years old. T. amurensis was 61 years old and the growth of Q. mongolica slowed a little. As the result of Shannon's index of species diversity, community Ⅰranged from 0.9578 to 1.1862, community Ⅱranged from 0.7904 to 1.2286 and community Ⅲranged from 0.8701 to 1.0323. The contents of organic matter and cation were low compared to uncultivated mountain soil and it were analysed to be inappropriate for tree growth.