A soundscape can enhance the acoustic environment of urban areas and support the sustainable development of green spaces. This study is based on field research on plant information and a perception questionnaire conducted in 30 urban park sample sites in China. The study analysed the differences in soundscape perception among different plant spaces using three dimensions: sound source dominance degree (SDD), sound source harmony degree (SHD), and soundscape perception evaluation. Additionally, five physical indicators of plant space were selected to quantify the effects of physical characteristics of plant space on soundscape perception in urban green space (UGS). The results indicated that there were impacts on soundscape perception. The evaluation of soundscape perception between different types of plant spaces revealed notable differences, particularly in open and enclosed spaces. All eight indicators demonstrated significant differences, indicating that soundscape perception was influenced by the type of plant space. Additionally, there was a significant correlation between plant space and soundscape perception. The evaluation of soundscape perception in three dimensions was related to several factors, including the degree of spatial enclosure, crown density, average tree height, the proportion of trees and shrubs, and the number of tree species. The dominant factor affecting sound source dominance was found to be the degree of spatial enclosure, followed by the average height of trees. Additionally, the diversity of trees affected the overall soundscape perception.