To fully use the biological potential of a sertain breed, it must fit into the specific environmental conditions, which in each zone differ in their specific characteristics (fertility and agrophysical state of the soil, hydrothermal regimes, insolation indicators, etc.). Knowing the individual reaction (adaptability) of the breed will allow it to be used in specific agrolandscapes, where it will provide maximum returns. The parameters of ecological plasticity, stability and homeostaticity of four soybean breeds and four breeds of field peas under sharply continental conditions in the south of Central Siberia are defined as adaptability criteria. It has been established that the Yakhont pea breed and the Sibiryachka soybean breed are more demanding on high growing conditions. Ruslan and Kemchug pea breeds and SibNIIK 315 and Sibniiskhoz 6 soybean breeds showed a change in yield corresponding to a change in growing conditions. Radomir pea breed and Zaryanitsa soybean breed are recommended to be grown on an extensive background, where they will give maximum returns at a minimum cost. The soybean breeds SibNIIK 315 and Sibniiskhoz 6 and the pea breed Kemchug were distinguished by their homeostatic index. They are characterized by lower yield variability with its high expression. Significant differences in yield stability, both of soybean and pea breeds were not observed, since Fф < F05.