The fungi of the genus Ophiocordyceps sinensis (Berk.) belong to entomopathogenic fungi. Ophiocordyceps sinensis has been used as a tonic and medicinal product in China for more than 2,000 years. A number of scientific papers have described the clinical use of this parasitic fungus with subsequent biological and pharmacological effects. The various chemical compounds identified in these fungi are responsible for a wide range of biological activity: cordycepin, cordycepic acid, D-mannitol, polysaccharides, nucleotides, proteins, amino acids, and unsaturated fatty acids. Our research focused on the determinations of the biologically active chemical compounds in extracts from cultivated Ophiocordyceps fungi using UV/VIS (Ultraviolet/Visible) spectrophotometry and NMR (Nuclear Magnetic Resonance) spectroscopy. The testing of antimicrobial activity of extracts against the collection strains of Escherichia coli and Staphylococcus aureus demonstrated that the percentage of RIZD (relative inhibition zone diameter) ranged from 83 % to 166 %. The increased antimicrobial activity against E. coli was observed in comparison with that against S. aureus.