During the 2008-2010 period on light grey pseudopodzolic soils the following birdsfoot trefoil varieties and populations were studied: Shumen, Nesebar, Kiten, Tryavna, Sadovo, as well as genotypes of the varieties: V. Podolyanskii (Russia), Dedinovskii (Russia), Martanskii (Russia), Zora (Serbia), Bokor (Serbia), and Smolenskii (Russia). Variety Targovishte 1 (St) was used for comparison. The objective of the study was to investigate chemical composition, including content of crude protein, crude fiber, crude ash, with a view to growing those having the highest quality in the fore-mountainous conditions of the Central Northern Bulgaria. Crude protein content reached the maximum during the second year of growth. The highest crude protein value was measured in the forage of the varieties Bokor (193.1 g.kg-1) and Dedinovskii (190.2 g.kg-1). The mean value of crude protein in all studied varieties and populations was 129.8 g.kg-1, and the degree of variability was low (CV=9.78%). The crude fiber increased after the first year, and the differences of the mean values in the second and third year were not significant. The lowest fiber content in the three years was reported in the varieties Podolyanskii (225.8 g.kg-1), Martanskii (277.7 g.kg-1) and Targovishte 1 (288.1g.kg-1). The variation of crude fiber was highest in the third year, and CV values indicated a low the degree of variability (8.31%). The degree of variation of crude protein and crude fiber was approximately equal between the different accessions. It was found that, for the conditions of light grey pseudopodzolic soils on average for the period, variety Dedinovskii showed the highest crude protein content (160.3 g.kg-1) while variety Martanskii had the lowest percentage of crude fiber(288.1 g.kg-1). On average for the experimental period, maximum quantity of ash was contained in the forage of variety V. Podolyanskii – 89.8 g.kg-1, and the mean value of ash was 81.3 g.kg-1.