The distribution and content of calcium ions in organelles, cytoplasm and celi walls of leaf mesophyll and epidermis of Sium latifolium air-water and terrestrial plants at various developmental stage was investigated. It was established that the relative content of Ca2+ in cells changed in relation to growth stage and environmental growth conditions. Moderate water deficit led to the increase of calcium content in chloroplasts and nucleus of palisade mesophyll, and in cell walls of adaxial epidermis of plants that were collected at flowering phase. At fruitage stage, water deficit led to the decrease of Ca2+ in chloroplasts and in cytoplasm of mesophyll cells and in cell walls of epidermis. The obtained results show that these data can be used as a basis for future studies on the mechanisms of calcium redistribution and the role of ion channels in plant cells under water deficit.