The assessment of the viability and stability of micromycetes stored in NCNM, as potential producers of active substances, for 15 years by different methods: subculturing, under a layer of mineral oil, lyophilized, showed that all are viable and retain their morpho-cultural characteristics according to strain passport. Some cultures kept under mineral oil Vaseline or infected during storage. The safest method of preservation for long-term storage is lyophilization. The viability of strains belonging to the genus Aspergillus after 15 years of preservation in lyophilized state varies in the limits of 71.0-87.2%; for the strains of the genus Penicillium - 65.2-86.8%, and for those of the genus Fusarium - 54.0-70.0%, in comparison with viability established immediately after lyophilization.