Objective: the purpose of the study is research of the changes in phenotypic and genetic characteristics of melanoma cells Mel Ibr cultured in growth medium with low concentration (5 %) of embryo calf serum. Materials and methods. Cell line Меl Ibr was pre-cultured in RPMI-1640 medium with 5 % FBS for 3passages, and then 200-400 cells were replaced on the Petri dish with a diameter of 60 mm and left in the incubator for 14 days to form colonies. Colonies of spindle form cells were cultivated in the same conditions for more than 30 passages. Cells were stained according to the method of Leishman to investigate the morphology. The expression of antigens was determined in the reaction of indirect immunofluorescence. Results. Exposure of Mel Ibr human melanoma cells to low concentration of embryo calf serum resulted in the appearance of a subclone with morphological, immunological and cytogenetical characteristics differed to those of parental cells. The subclone cells distinguished with spindle form, more small size, large nucleus which broadcasted on whole cytoplasm, formation spheroid and sharply reduced percentage of HLA-DR (+) and CD54 (+) cells, a significantly elevated percentage of CD63 (+) cells, and appearance of CD133 (+). The subclone karyotype differed to those of parental cells. Conclusoin. The subclone cells were characterized by the same features as stem tumor cells and could be use as tumor progression model.