Morphofunctional state and differential potential of cultured osteoblasts and osteogenic precursor's cells under real and simulated microgravity are in the focus of presented review. Summary of data of osteoblast cell responses to altered microgravitational circumstances are discussed. Mesenchymal stromal cells are the population of multipotential precursors of adult bone marrow stroma able to differentiate into osteogenic. Adipogenic and chondrogenic lineages. Recent studies have demonstrated that multipotential mesenchymal stromal cells can be the real candidates to gravity-responding cell type and can be involved into space flight-induced osteopenia. These findings determine the necessity of more detailed study of its biology in vitro and in vivo.