Physicochemical properties of starch isolated from the naked barley seeds durin germination were investigated. The germinated barely seeds showed an apparent increase in amylose component of the starches, and water binding capacities of the starches decreased initially and then increased with longer germination time. The size frequency distribution of starch granules showed that the granules larger than 20.2 .mu. in diameter were preferentially degraded, and moreover the rate of degradation was higher than that of granules of any other size. It was apparent that the mean diameter of granules was 12.7 .apprx. 20.2 .mu. at all stages of germination. The results of differential scanning calorimetry, swelling power, solubility and X-ray diffraction patterns of starch granules isolated at various stages of germination showed little changes during germination. Scanning electron microscopy revealed that the starch granules have been damaged extensively by degradative enzymes during germination, but all the starch granules were not degraded uniformly.