Resumo. This paper investigates aspects of classification and reports the diversity in a remnant of a riparian forest in Lages, Santa Catarina. Twenty-five plots were allocated along the river, and all trees with diameter at breast height (DBH) greater than or equal to 5 cm were measured. The community had 67 tree species and a canopy with emergent species. The diameter distribution showed a self-regenerating community, with a large number of small trees and high values of density and basal area per hectare. The classification separated the sites with higher basal area, presence of Cabralea canjerana and Myrcia hatschbachii and the sites with presence of generalist species Celtis iguanaea and Ilex brevicuspis, denoting a large environmental variability in this forest.