Cryogenic freezing mainly uses low temperature refrigerants(e.g.liquid nitrogen,liquid carbon dioxide(CO2),etc.) as cooling medium to achieve low temperature through heat conduction and convection.The glass state may reduce damage of bacterial cell with rapid freezing rate.Cryogenic depth frozen is superior to freeze drying due to its high frozen quality,low devitalization rate,high efficiency and low cost for investment and equipment maintenance in the production of probiotics.The particle cryogenic refrigerating device is widely used in manufacture of probiotics and precedes to traditional facility.Although cryogenic freezing process results in exocellular and intracellular freezing damages,permeable or impermeable protectants can be used to reduce those damages.