Soybean (Glycine max (L.) Merr.) is used to a large extent as high-protein feed ingredient in livestock production. The increasing demand in Moldova and Europe for GMO-free soybean products against the backdrop of the increasing cultivation of genetically modified seeds requires the expansion of national breeding activities and the development of domestic soybean varieties. Securing the domestic protein supply, in particular in the organic production of livestock and poultry feed, presupposes the availability of climatic adapted, high and constant yielding varieties with high protein content. It is very important to create express methods for the exact identification of the main physiological and genetic systems that increase yield in a given environment, rather than the genetic characteristic of a quantitative trait that will necessarily change in another environment for selection purposes. Indices are widely used in breeding technologies. However, their use requires careful analysis of their informational content against the backdrop of various limiting factors of the external environment. Studies carried out in the Institute of Genetics, Physiology and Plant Protection of Moldova dedicated to the breeding lines of soybean showed that when evaluating the productivity in the context of the “genotype-environment” relationship, the greatest informational content was obtained when estimating four indices in aggregate: mass of seeds from the plant/ height of plants, number of seeds on the plant / number of productive nodes, mass of seeds from the plant/ number of beans on the plant, mass of seeds from the plant/ number of seeds on the plant. Correlation analysis revealed reliable relationships between yields of selection lines of soybean and selection indices, r = 0.26-0.90. Five most productive lines are identified according to the cumulative assessment of the indices with a yield significantly higher than the grade standard by 35.5-90.7%. Based on this sample, the evaluation of soybean lines by quantitative characteristics using selection indices in the interaction of "genotype-environment" factors was carried out. According to the aggregate assessment of indices: five most productive lines were identified: d. 62, d. 64, d. 56, d. 69, d. 81 and d. 87 with a yield of 2.42 t/ha – 3.4 t/ha, the “Deia” standard variety -1.78 t/ha.