Using the Chlorella cells which had been uniformly labeled with <TES>$^{32}P$, the distribution of phosphorus in various fractions of cell material was investigated. Uniformly <TES>$</TEX>^{32}P$</TEX>-labeled Chlorella cells were further grown in a P-free medium, and some protions of the cells were taken out at intervals during the culture, and subjected to analyze the contents of <TES>$^{32}P$ in various fractins of the cell constituents. 2. Analysis of the <TES>$</TEX>^{32}P$</TEX>-labeled Chlorella cells showed that the highest in P-content was the fraction of RNA followed by those of lipid, RNA-polyphosphate complex, acid-insoluble polyphosphate, acid-soluble polyphosphate, DNA and protein. 3. During the culture of <TES>$^{32}P$</TEX>-labeled Chlorella cells in a P-free medium, amounts of phosphate in DNA, protein and lipid fractions increased, while the P-contents in the fraction of RNA-polyphosphate complex decreased as well as those of acid-insoluble polyphosphate and acid-soluble polyphosphate fractions. 4. It was inferred that phosphorus used in the syntheses of DNA and protein was taken from polyphosphates of the cells, and RNA-polyphosphate complex would play an important role as a phosphate pool.