In order to observe the phosphate metabolism in chloroplast, the contents of inorganic phosphate and various compounds in chloroplast from spinach leaf tissues were investigated during the reaction in the light and dark in the reaction mixture and the turnover of phosphate in chloroplast was compared with that of whole cell system: 1. The phosphorus of DNA in chloroplast appears to be transferred from inorganic phosphate, while in whole cell system from phosphate pool. 2. $^{32}P-phosphate$ content of acid soluble fraction in chloroplast as well as in whole cell system was more increased in the light than dark during the reaction. It was noted to be caused by the stimulation of sugar phosphate synthesis in the light. 3. It was confirmed that polyphosphate exists in chloroplast as well as whole cell. Acid insoluble polyphosphate content in whole cell system was significantly decreased during the reaction and the similar tendency was also observed in chloroplst. It is, therefore, considered that acid insoluble polyphosphate also play an most important role as a phosphate pool respectively in chloroplast and in cytoplasm. 4. Protein and lipid phosphorus in chloroplast as well as whole cell system were transferred from acid insoluble polyphosphate.