The oocyte maturation is regulated by calcium intracellular signaling. This signaling is dependent on the influx of calcium ions and on the state of intracellular calcium stores. In this study, intracellular calcium deposits were observed in the nucleus,the mitochondria, the cytoplasm, and on the surface of lipid droplets. The distribution of calcium deposits in oocytes changed during folliculogenesis. On the basis of discovered data about the amounts of calcium deposits in nuclei, mitochondria and cytoplasm during folliculogenesis it was concluded, that these changes may be involved in the regulation of the meiotic competence of oocytes.