Actinobacteria, the biotechnologically valuable bacteria, are the dominant class of the Bacteria domain in most soils. Approximately 45% of all discovered bioactive microbial metabolites are produced by Actinobacteria. The aim of the research was to study the community structure of Actinobacteria class from a typical chernozem. The research was carried out in the long-term field experiment of the “Biotron” Experimental Station of the Academy of Sciences of Moldova in two crop rotations (with and without alfalfa). Characterization of the compositional diversity of the soil microbiome was achieved by the 16S rRNA amplicon sequencing (Scientific Center "Genomic Technologies, Proteomics and Cell Biology" of FSBSI ARRIAM, St. Petersburg, Russia). The results of the investigations demonstrated that Actinobacteria had the highest relative abundance (8.2%) compared to 3 other classes (Thermoleophilia, Rubrobacteria, Acidimicrobiia) of the phylum Actinobacteriota, identified in the soil of the the long-term field experiment of the “Biotron” Experimental Station (Chişinău ). Actinobacteria had the highest relative abundance in the Mineral fertilization and Control variants of both crop rotations, and the lowest abundance was in the Organic fertilization (postaction) variant. The class was represented by 10 orders of bacteria. The orders Propionibacteriales (2.5%), Micrococcales (2.3%) and Frankiales – (1.2%) had the highest relative abundance. The order Propionibacteriales was more abundant in the variants with mineral fertilization of the both crop rotations, and in the soil of the forest shelterbelt, the order Micrococcales - in the variants Control and Forest shelterbelt, the order Frankiales - in the variants Control of the both crop rotations, and Mineral fertilization of the crop rotation without alfalfa. The rarer orders with abundance ≤ 0.1 were Corynebacteriales, Kineosporiales, Streptosporangiales. The maximum abundance of these rare orders was observed in the following variants: Corynebacteriales - in the Forest shelterbelt, Kineosporiales - in Control of the both crop rotations, and Streptosporangiales - in Mineral fertilization of the crop rotation with alfalfa. The order Streptosporangiales had the lowest abundance in the soil of the Forest shelterbelt (<0.01%). The orders included 20 families, and 34 genera. Most genera (7) were identified in the Pseudonocardiaceae family. The most abundant genera were: Microlunatus – 1.5% (the Propionibacteriaceae family), Blastococcus – 0.9% (Geodermatophilaceae), Agromyces – 0.5% (Microbacteriaceae), Pseudonocardia – 0.4%, (Pseudonocardiaceae), Streptomyces – 0.4% (Streptomycetaceae). The genus Microlunatus was present in all variants of the experiment with the abundance > 1%, it included 25 species of aerobic, chemo-organotrophic bacteria, some species can oxidize nitrates in anaerobic conditions and accumulate phosphates. The genus Blastococcus (12 species) had the lowest abundance in the uncultivated land of the Forest shelterbelt, and the highest abundance was determined in the Control and Mineral fertilization variants of the both crop rotations. The genus Agromyces (45 species), considered as an indicator of healthy soils, reached the maximum abundance in the uncultivated soil of the Forest shelterbelt and the unfertilized soil of the Control variants of the both crop rotations. The metagenomic research of the typical chernozem demonstrated the presence of a great diversity of Actinobacteria with biotechnological potential both in the soils of the agricultural plots and of the forest shelterbelt. Finding correlations