The research was carried out at the “El Huayo” Arboretum of CIEFOR, Puerto Almendras. With the objective of determining its forest structure and carbon stored in the biomass of forest species of a mid-terrace forest. The results present a floristic composition of 566 trees, 33 families, 87 genera, 109 tree species, with DBH≥ 10cm. The familyLecythidacea and Fabacea (18.02% and 16.96% representation in the study area) are the ones with the greatest presence in plot VIII. There are 17 forest species most representative of 50% of the studied area, beingSchweilera coriacea, Pouroma tomentosa and Tachigalia bracteosumthose with the highest ecological importance value index (IVI). There is a total of 288369.89 Kg of aerial biomass, which represents 180231.18 Kg/ha and theEschweilera coriaceaIt has the greatest amount of biomass with 46815.03 Kg (29259.40 Kg/ha) and when quantifying 90.12...