The content of condensed inorganic polyphosphates in high productive and low productive Streptomyces aureofaciens strains has been determined. At all the stages of growing the quantity of these compounds in low productive strain is 8-10-fold higher than in high productive strains. Maximum accumulation of condensed inorganic polyphosphates in both the strains Str. aureofaciens corresponds to the end of logarithmic phase of growth. In both strains the presence of two enzymes of polyphosphate biosynthesis -- ATP:polyphosphate-phosphotransferase and 1.3-diphosphoglycerate:polyphosphate-phosphotransferase has been revealed as well as the presence of the enzymes of their utilisation -- polyphosphate:D-glucose-6-phosphotransferase, polyphosphate-phosphohydrolase, tripolyphosphosphate-phosphohydrolase and pyrophosphate-phosphohydrolase. The difference in the activity of 1.3 diphosphoglycerate: polyphosphate-phosphotransferase and polyphosphate-phosphohydrolase has been revealed in both strains studied. On the basis of the data obtained it is supposed that there is a possibility of using phosphorus and energy of high molecular inorganic polyphosphate in the biosynthesis of so called products of "secondary metabolism".