During storage of slaked lime made by wet slaking，it is said that the particle size distribution might change．In order to find out the change in particle size distribution with the passage of time，we placed slaked lime in two types of containers: a plastic container and an unglazed jar．Quicklime burned from limestone by a rotary kiln was used and the amount of water for slaking to quicklime was varied from three times to fifteen times．Particle size distribution was measured once a month by SALD-3000，Shimadzu Corporation Co．Ltd．and SEM images were obtained by 5800LV，JEOL，Co．Ltd． It became clear that particle size distribution was unchanged until the clear layer at the top of the container was taken away．A small ratio of water to quicklime in slaking caused a wide distribution of particle size，but the homogeneity of the particle size of the slaked lime increased with the passage of time
