The aim of this study was to analyze the floristic composition and structure of tree-shrub vegetation under a stand of Anadenanthera peregrina, in the municipality of Naque, Minas Gerais State, Brazil. The study was conducted in an area of approximately 10 ha within Anadenanthera peregrina population owned by Celulose Nipo – Brasileira SA (19°15’05’’S e 42°20’30’W). Ten random plots (20 x 50 m) were established to sample individuals with CBH (diameter at breast height) ≥ 15 cm (Class I). It was installed a subplot of 10 x 10 m in the center of each plot to sample individuals with total height ≥ t 1.30 m above the ground and CBH < 15 cm (Class II). Individuals in 20 x 50 m plots were classified according to their dispersal syndromes and successional guilds. In addition, it was performed the diameter distribution of samples. 510 individuals were found in Class I, belonging to 10 botanical families, 15 genera and 15 species; in Class II, 47 individuals from 10 families, 14 genera and 14 species, with the Sorensen similarity index equal to 48%. Classification of successional species sampled in classes I and II showed higher species richness in early secondary succession, with the group formed by pioneers and early secondary totaling 93.5% in Class I and 93% in Class II. Regarding dispersal syndromes, 60% of species in Class I are wind-dispersed. Diameter distribution by diameter class of Anadenanthera peregrina and other species were classified into reverse J-shaped distribution.