It is known that actinomycetes have the ability to synthesize a wide range of biologically active substances as amino acids, enzymes, antibiotics, plant hormones, lipids, vitamins etc. Saving the composition of the population which synthesizes biologically active substances is an urgent problem in the field of biotechnology, because all streptomycetes are more susceptible to natural variability. An effective way to store them is lyophilization. Lyophilization was performed in vials using the Labconco freeze dyer, the cryoprotective medium – gelatin 2,5% + glucose 7,5% and rehydration medium – distillate water. The survival rate was counted by logCFUml-1. It was established that the population of the collection strain Streptomyces canosus CNMNAc- 02 is represented by white aerial mycelium and gray substrate mycelium colonies of 2 sizes: 4–7 mm (45,3%) and 1 mm (54,7%). After lyophilization and freezing at -20°C, were observed three types of colonies of aerial mycelium: 79.3% white color (4–6 mm), 14.4% gray color (7,4 mm) and 6.3% white color (1 mm), and substrate mycelium, respectively: uncolored, gray and whitish . After lyophilization and freeze at -50°C, 89.5% of colonies were with white color aerial and substrate mycelium and 10.5% of colonies – with gray colored aerial and substrate mycelium, sizes were 4.7 and 4.6 mm respectively The strain Streptomyces massasporeus CNMN-Ac-06, isolated from the soil of Moldova, before lyophilization presented three types of colonies: 75.6% – with pale gray aerial mycelium and brown substrate mycelium, 15.4% – with white aerial mycelium and pink substrate mycelium, and 8.9% – with white with a purple center aerial mycelium and purple substrate mycelium. After lyophilization and freeze at -20°C were obtained 2 types of colonies: with pale gray aerial mycelium and brown substrate mycelium (89.8%) and with white aerial mycelium and pink substrate mycelium (10.25). After freezing at -50°C – the same 2 types of colonies was observed, in the case of freezing t=80ºC was found one type colonies. The survival rate of the strain S. canosus CNMN-Ac-02 after lyophilization fluctuated depending of freezing temperature: 99.3% (t0=-20°C) , 90.3% (t0=-50°C), and 96.3% (t0=-80ºC). The survival rate of the strain S. massasporeus CNMN-Ac-06 was: at t0=-20°C – 75.9%, at t0=-50°C – 75.7%, and at t0=-80ºC – 53.1%. Thus, for the better preservation of streptomycetes, it is necessary to avoid drastic changes in the population by the use of individual methods of lyophilization. The optimal freezing temperature before the lyophilization of the studied strains is – 50°C.