The subject of the study was genetic and phenotypic characteristics of Beluga (Huso huso (Linnaeus, 1758)) grown in the warm-water aquaculture at the “Selets” fish farm (the Republic of Belarus). Molecular-genetic analysis was performed using STR-markers and species-specific PCR revealed the absence of hybrid individuals in analyzed broodstock of Beluga sturgeon. Affiliation of individuals to the Caspian population was established based on the sequence analysis of the 367 bp region of mitochondrial D-loop. Using six STR loci, the population structure was analysed. The population structure and gene pool of the only broodstock of Beluga sturgeon in Belarus was compared with domesticated Beluga sturgeons from the Russian Federation. The analysis showed a lack of genetic variation and the heterozygote excess in Beluga sturgeons from the Belarusian farm. Analysis of morphometric indicators revealed that the conditions in which the Beluga broodstock is kept at the fish farm “Selets” should be improved. Using ultrasound scanning, the following stages of gonad maturity were established: stages II, III and IV in males; II, II semi-fatty, II fatty, II-III in females. The beluga broodstock at the fish farm “Selets” is mainly represented by females (the females exceeded the males by 2.3 times in terms of their number).