Extracts of 9 species of the Caryophyllaceae family were screened for antimicrobial activity on the example of 17 types of strains of microorganisms. The inhibitory activity of 7 butanol extracts has been shown against a number of pathogenic strains belonging to the species Mycobacterium smegmatis, Phroteus mirabilis, Serratia marcescens, Staphylococcus aureus, Streptococcus faecalis. The extracts studied were most effective on the bacteria Bacillus cereus and Bacillus subtilis. It was found that all the studied plant species of the genera Lychnis and Silene contain ecdysteroids and flavonoids. The isolated individual compounds contained in all the studied species showed antimicrobial action on strains of a number of bacteria: the ecdysteroid 20-hydroxyecdysone suppressed the growth of the strain of R. mirabilis, while the flavonoid shaftoside inhibited strains of bacteria S. aureus, B. cereus, B. subtilis, R. mirabilis, M. smegmatis. Gram-negative bacteria Salmonella typhimurium, Klebsiella pneumoniae, Shigella sonnei, Pseudomonas aeruginosa are not susceptible to the antimicrobial action of extracts under experimental conditions. Determination of antimicrobial activity was carried out by methods – diffusion and joint incubation of plant extracts and cells of test strains of microorganisms in a liquid nutrient medium LB at the ratio sample : medium 1 : 2 and 1 : 1. Increase in the concentration of secondary metabolites of ecdysteroids and flavonoids in experiments with butanol complexes of substances with a sample ratio the 1 : 1 environment led to an increase in antimicrobial activity up to the complete inhibition of Gram-positive bacteria B. subtilis and B. cereus by extracts of plant species Silene graefferi, S. colpophylla, S. sendtneri, S. linicola, S. jenisseensis S. viridiflora (seeds) and individual shaftoside.