Based on the 103 soil samples collected from various locations in the provinces of Thai Nguyen, and some neighboring provinces, the authors have isolated 74 strains of actinomycetes of the genus Streptomyces. Through inspection activity antibiotics of actinomycetes strains isolated, 50 strains (up 67.6 percent) have activity against microorganisms test. In particular, there are 8 species (16 percent) with all 3 active bacteria Gram (+), Gram (-) and mold. For the purpose of selecting the strains with high antibiotic activity to continue research, the authors have selected the 5 strains of actinomycetes are denoted respectively DH2.3, DH2.4, BG4.2, BK2. 2, TT1.2 and test their antimicrobial activity over time and subcultures preserved strains in two different conditions is 4°C and - 20°C within the laboratory. To assess the change in their antibiotic activity, thereby determining the most suitable storage conditions on the basis of the existing equipment of the laboratory.