The paper discusses the joint effect of cytokine 6-BAP and different spectra when illuminated by LEDs on the morphological parameters of growth, development and the content of phenolic compounds in plants of St. John's Wort (Hypericum perforatum L.) of two genotypes – wild and cultivated (cultivar Zolotodolinskiy) – in conditions of in vitro cultivation.It is shown that the light of different spectral composition and the hormonal composition of medium influences the morphogenesis, the productivity of biomass and the synthesis of phenolic compounds by plants under in vitro cultivation conditions.It is established that the combination of the light spectrum, and the hormonal composition of nutrient medium may substantially increase the content of soluble phenolic compounds in both wild and cultural genotypes of Hypericum.The analysis of the obtained results shows a direct correlation dependence of the content of phenolic compounds on the number of shoots and their mass. The correlation between the number of shoots and the content of phenolic compounds has a direct character and strongly expressed.