By the method of exhaustive hydroparodistillation, essential oil was obtained from Siberian pine (Pinus sibirica Du Tour) and Siberian fir (Abies sibirica Ledeb.), growing on the territory of the Krasnoyarsk territory. Separate fractions of oil were obtained: the first one after 45 min from the beginning of distillation, the second – after 2 hours, the third – after 5 hours, the fourth-after 10 hours, the fifth fraction was collected after the end of hydrodistillation. The antimicrobial activity of separate fractions of essential oil of P. sibirica and A. sibirica was studied against strains of opportunistic microorganisms: Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus 209p, Micrococcus luteus, Acinetobacter baumanii, Candida albicans. The performed studies showed that all the studied samples of essential oils showed either bactericidal or bacteriostatic activity against the strains of microorganisms taken in the experiment, except Pseudomonas aeruginosa. The type of activity displayed depended on the type of strain and sample of essential oil. It is noted that the sensitivity of the experimental strains to the components of the essential oils of P. sibirica and A. sibirica decreases during the transition from the first to the last fraction. We assume that, apparently, this is due to a decrease in the number of monoterpenes in the composition of oils.To study the antiradical activity, the reaction of essential oil components with a stable free 2,2-diphenyl-1-picrylhydrazyl radical was used. Antiradical activity of both whole essential oils of P. sibirica and A. sibirica and their separate fractions was established. There was an increase in antiradical activity with a decrease in the content of monoterpenes in the composition of essential oil.