Was created and constantly replenished the Branch Collection of strains of lactic acid bacteria, industriallyvaluable, in the Practical Scientific Institute of Horticulture and Food Technology, Republic of Moldova, Chisinau. It is known that lyophilization represents the process of drying a biomass by excision of a liquid from the frozen cell in conditions of lowered pressure [1]. It is one of the most progressive methods of microorganisms’ conservation. We had the task to determine the optimum parameters for the lyophilization of a collection of lactic acid bacteria cultures for long-term storage and keeping the valuable biotechnological properties of the microorganisms. The lyophilization process has been investigated in the laboratory of food biotechnology of the Practical Scientific Institute of Horticulture and Food Technology using the „Freeze Dry System” (LABCONCO) modern equipment with programmed control in which the freezing and drying occurs in one chamber. Cultures of local mesophil and thermophil strains of lactic acid bacteria have been used in researches in an exponential phase of development. Bacterial cultures were admixed with protective medium. It is known a wide range of parametrical value of a lyophilization which depends on bacterial culture, protective medium, the known potential of equipment [1, 2, 3, 4]. It has been established that lactic acid bacterium with titrated acidity 75... 100 ˚T the freezing of the free and bound moisture when the biomass gets the form of the monolithic frozen block occurs at a temperature of minus 35˚C and lower. Therefore for the prevention of biomass foaming phenomenon, which leads to denaturation of proteins, the dehydration under pressure has to be started after achieving the established eutectic biomass temperatures. The values of positive temperatures of the dehydration process of a biomass have been defined also. During experimental developments on the „Freeze Dry System” (LABCONCO) equipment optimum parameters of a lyophilization process have been picked up. As a result of a lyophilization, samples of lyophilic bacterial cultures which represent porous crumbling tablets of cream color with residual humidity of 1,9 % have been received. The developed parameters of lyophilization process using the „Freeze Dry System” (LABCONCO) equipment have provided an optimum dehydration of bacterial mass of lactic acid bacteria strains collection, conservation of viability and biotechnological activity of microorganisms.