A study was made of proteolytic activity of the microorganisms Proteus and Bac. cereus, as well as of infected extract from raw meat. Subject to study were also the effects of the temperature, storage and microbial association on the production of exoproteases. The results indicate an increase in the proteolytic activity in the course of storage at room and decreased temperatures and a lowering of the soluble protein amount in the samples, which attests to an active process of spoiling. Association of the bacteria in question appears to be a factor with a certain effect of protease repression. It is necessary to exercise control over the amount of the microorganisms in foods with a high content of protein, and to revise the times of meat storage in refrigerators.