Various methods of storage (as soil cultures, in peptonecorn agar, and in the freeze-dried state) of the thermotolerant actinomycete Thermoactinomyces vulgaris RA II-4a, protease producer, were studied. The best method providing a high level of proteolytic activity was shown to be freeze-drying and subsequent selection of the most active variants. The optimal temperature for the storage of the freeze-dried culture was 4 degrees C. During a prolonged (12 months) storage of the actinomycete under the above conditions its proteolytic activity grew by 84.6%.