The study of the effect biologically active compound of the steroid type verbascoside, isolated from Verbascum densiflorum bertol., showed the high responsiveness of young fruit bearing plants of pear varieties Noyabrskaya and Vystavochnaya. The stimulating effect of verbascoside on the weight and leaf area, net productivity of photosynthesis, as well as functional features of these processes in the dif-ferent pear varieties during the growing season was revealed. Verbaskoside actively influences the growth and development of pear plants, creating a stabilization of the hormonal balance by changing the biological activity of endogenous growth regulators of IAA and quercetin and their ratio for a certain phase of vegetation. The use of verbascoside is one of the ways to optimization of vital functions and increasing of yield of pear plants.