Abstract: In this study, a comprehensive investigation was carried out in Yanbian county, and which is located in the lower reaches of Yalongjing river basin, with high mountains and deep valleys, rugged terrain, complex and diverse climate and rich species. The results showed that there were 881 species of woody plants, belonging to 338 genera and 99 families, including 6 national key wild protected plants and 485 evergreen broad-leaved species, accounting for 55.05% of the total species. The flora had diverse geographical elements and complex composition of families and genera, with 49 families and 69 genera distributed in the pantropical zone, accounting for 49.50% of the total families and 20.41% of the total genera, followed by 18 families and 47 genera distributed in the north temperate zone, accounting for 18.18% of the total families and 13.91% of the total genera. In addition, the vegetation had the vertical distribution characteristics of sparse shrubs, evergreen broad-leaved forest, subalpine coniferous forest and alpine shrubs.