The short harvesting season together with the soft texture, limit the availability of high-quality sweet cherries on the market for longer period. An essential element that builds up the structure and the resistance of cell wall and is calcium. To have high quality fruits, it should be applied by farmers in the orchard, but has a higher absorption rate while application in the postharvest hydro-cooling water. The aim of following study was to investigate the influence of calcium chloride (CaCl2) added to hydro-cooling water on physiological and biochemical parameters of Regina sweet cherry varieties. The research was carried out in 2020. The tested CaCl2 concentration in water at 0oC was 0.2%; 0.5%; 1.0% and 2.0% where the sweet cherries were immersed during 5 min. After hydro-cooling, fruits were stored in modified atmosphere packages produced by Stepac, Israel for 2 and 4 weeks. It was established the gases and atmosphere balances in packages and the organoleptic, physiological and biochemical parameters of fruits. The increase of Ca content in hydro-cooling water in comparison to control showed improvements in weight stability, acidity, firmness, soluble solid content and vitamin C with the best results at 0.5% and 1.0% CaCl2 content. Pedicel browning was reduced by CaCl2 at 0.2% and 0.5%, but presented higher effect at 1.0% and 2.0%.