The floristic diversity in two plots of 0.1 ha of two subandean forest, in Amazonian (La Campucana, Putumayo) and Pacific (Narnbi, Narino) Andean slopes at southwestern Colombia, was studied. The La Campucana forest was more diverse (269 species, 69 families and 158 genera) than Nambi forest (205 species, 59 families and 122 genera). Rubiaceae was the most diverse family in both localities, followed byAraceae and Melastomataceae in Nambi and Lauraceae and Sapotaceae in La Campucana. The distribution of life forms ts as follows: there were 32% trees, 28% treelets in Nambi, and herbs and climbers are structurally more important than shrubs, lianes and hemiepiphytes. In La Campucana there were 49% of trees, 22% treelets; herbs and shrubs were less important while the lianas were more important. Species with dbh > 2.5 cm were more abundant in La Campucana than in Nambi. The number of individuals was higher in La Campucana (1444) than in Nambi (1349). At the specific level the similarity between regions was low. The diversity and dominance indexes showed that the two sampled forests were highly diversified.