We made a compositional and structural analysis in a subandean forest fragment in the municipality of Bolivar; area affected by deforestation, habitat loss and expansion of agriculture being stressors that have limited the development of these fragments. Forest is located between 1 400 and 1 800 m, at 24 degrees C and 2 000-3 000 mm/year. We made 10 transects (100*5 m), we recorded types of growth such as trees, shrubs, herbaceous, palmoid, liana, epiphyte, hemiepiphyte, parasite, tree fern and morphological data. We assessed families and genera composition using diversity, dominance, equitability and similarity indexes; IVI, IPF, IVF and frequency distribution (altitude, coverage, DAP). We recorded 102 families, 257 genera and 483 species, with 73 dicotyledons (72 %), 13 monocotyledons (13 %) and 15 pteridophytes (15 %). Families with the highest genera and species number were: Rubiaceae (15 genera/29 species), Piperacae (2/25), Gesneriaceae (11/19), Melastomataceae (8/19), Solanaceae (4/16) Araceae and Urticaeceae (7/15 each one). Genera with the highest species number were: Piper (16 species), Miconia (10), Ficus, Peperonia and Solanum (9) Anthurium and Passiflora, Siparuna, Pilea and Zanthoxylum (6). Dominance and diversity indicated species uniformity, supported in the forest equitability. The similitude between transects is 24 % denoting a high species turnover. The herbaceous growth was the better represented with 56 families and 166 species. This research showed a high diversity and new records for Santander, with Passiflora engleriana Harms Endangered (EN), Aiphanes concinna H.E. Moore (Near threatened, NT), Miconia neomicrantha Judd & Skean and Guarea kunthiana A. Juss. (Low Concern, LC).