Resumo. A survey of the tree community of a ombrophilous upper montane forest, situated in Poços de Caldas, Brazil (1200-1575 m of altitude; 21°46'25"S, 46'24"10"W) was carried out in order to assess its environmental and structural variation. The physiognomic (density, basal area and distribution of size of the trees) and community structure (composition, distribution and diversity of species) were analyzed through 22 plots of 5 x 100 m, where the tree individuals with diameter at breast height ¿ 5 cm were sampled. The topographic variables were measured and the surface soil samples were collected to obtain their chemical and texture attributes. The survey resulted in 53 botanic families, 104 genera, 178 species and 1963 individuals, as well as four soil classes: distrofic and eutrofic Argisoil, Cambisoil and Litolic Neosoil, distributed sequentially from the hilltop to the base of the fragment. The canonic correspondence analyses showed a gradient of tree species distribution mainly correlated with variations of quotas, magnesium content (Mg++) and aluminum saturation (m).