The paper deals with the results of a research of changes in antimicrobial activity of strain Streptomyces levoris CNMN-Ac-01 on synthetic and complex media after long-term storage by subculturing (10 years). Antimicrobial activity was determined by the disk diffusion method, as test cultures were chosen opportunistic pathogenic bacteria and fungi spread in the Republic of Moldova. It was experimentally proved that the strain lost antimicrobial activity to a greater extent in relation to opportunistic pathogenic fungi, especially after cultivation on a complex medium (by 20.0-23.5%), while on a synthetic medium Czapek it is less (8.37-22.2%). It was established that the strain isolated from the soil of the Republic of Moldova differs from other strains of the same species in its ability to inhibit the growth of such fungi as Aspergillus flavus, Penicillium expansum and strains of the genus Fusarium. Studied strain has the ability to synthesize not only antibiotics levorin and levoristatin, but also probably, and other substances with antifungal activity.