Fresh, dried or preserved, forage legumes are highly suitable for use as roughage in the animal diet because of their richness in protein, vitamins, and mineral matter. Previous work on forage legumes breeding for improved quality has mostly focused on increasing the crude protein content of these crops. Another major parameter of forage legume quality, especially from the point of view of ruminant nutrition, is the in vitro digestibility of dry matter. Values of both these parameters decrease with age in all forage legumes due to a reduced leat to stem ratio and lignification. The decrease in digestibility after budding comes as a result of an increased lignin content and a rise in the proportion of starch polysaccharides. In the context of forage quality, especially important from the point of view of ruminant nutrition is the relation between structural and nonstructural carbohydrates. Structural carbohydrates include neutral detergent fiber (NDF) and acid detergent fiber (ADF), while non-structural ones are mostly starch. The latest efforts in forage legume breeding should encompass certain specific traits in order to completely fulfill the needs for safe feed in animal husbandry.