Abstract: Since 2015, Pujiang County had carried out planned logging of Pinus massoniana Lamb. which died due to infection with pinewood nematode disease. In order to understand the community structure, stand quality, and succession characteristics of the public welfare forest arbor layer after clearing Pinus massoniana, this study was based on the survey data of 124 fixed monitoring sample plots in Pujiang County public welfare forest in 2015 and 2019. The arbor layer structure of different forest types, the structure of different tree types, the composition of dominant species, and the diversity of tree species were studied. The results showed that: 1) From 2015 to 2019, 52 pine forest sample plots were reduced, and the remaining 4 samples accounted for 3.23% of the total number of public welfare forest plots. 2) The diameter class distribution of deciduous broad-leaved trees and evergreen broad-leaved trees were similar, showing an inverted "J" shape, indicating the good renewal of broadleaf populations. Although the number of Pinus massoniana decreased greatly in the past four years, there was no significant change in the distribution characteristics of its diameter class; while, due to the lack of subsequent renewal individuals, the population trend was a decline type. 3) The importance value of Pinus massoniana decreased by 7.99% from 2015 to 2019. After the diseased Pinus massoniana was cleaned up, the important values of Schima superba, Castanopsis sclerophylla, Castanopsis eyrei, Quercus serrata var. brevipetiolata, Cerasus serrulate and Toxicodendron sylvestre had increased significantly. 4) From 2015 to 2019, the diversity and evenness of arbor layers in broad-leaved forest decreased significantly due to the disappearance of some deciduous broadleaf tree species and the significant increase in the numbers of Schima superba. In 2015, the Shannon-Weiner index showed that broad-leaved forest > broadleaf-conifer > pine forest > fir forest > bamboo forest. The diversity of broad-leaved forests was significantly higher than that of fir forests and bamboo forests, and there was no significant difference from other forest types. In 2019, the Shannon-Weiner index showed broadleaf-conifer and broad-leaved forests > pine forests > fir forests > bamboo forests. There were no significant differences in the diversity of forest types except bamboo forests.