Palabras clave: Cynodon plectostachyus, Leucaena leucocephala, Megathyrsus maximus, sistemas silvo- pascicolas AbStRAct: The objective of this study was to evaluate the nutritional quality of the forage components of a SPSi based on Leucaena leucocephala associated to improved pastures, as well as its bio- mass production. The forage production was determined at several moments of the year and the nutritional quality was evaluated through the Cornell model. The soluble protein proportion (fraction A) was similar between the grasses and L. leucocephala, and represented as minimum 34 % of the total protein. The proportion of protein B 2 (intermediate degradation) of the legume was higher than that of the grasses (53,7 vs. 30,2 %, respectively). Protein B 3 of the diet (slow degradation) was around 22 % of the total protein, and more than 71 % of it can be considered degradable in rumen. L. leucocephala showed a higher concentration of soluble carbohydrates (16,7 %) and lower quantity of fraction B 2 (14,94 %) than the grasses. Concerning the biomass availability, a production of 19,26 t DM/ha year -1 was reached. It is concluded that in SPSis a high quantity of quality forage is produced throughout the year, and that this offer is sufficient to cover the requirements of ruminants.