To explore the method of green and safe storage of processed grain, 2 kinds of high quality milled long-grain-nonglutinous rice were stored in underground granary in high temperature and high humidity area to determine regularly the quality indexes, including moisture, the amount of broken kernels, small broken kernel rate, chalky kernel rate, yellow-colored kernel, amylose content, tasting score, color and odor, unsound kernel and pest population density. The results showed that the moisture of the testing rice declined slightly and their inhibition period against pest was 13 months; the indexes of small broken kernel rate and color and odor were not significant changes, the amount of broken kernel, yellow-colored kernels and unsound kernels increased a little, amylose content increased gradually, but none of them decreased the quality level of rice. While the chalky kernel rate increased significantly and the tasting score decreased significantly, which decreased the quality level of rice. It shows that the underground granary has a good effect of moisture retention, fresh-keeping and pest control. The storability of high quality milled long-grain-nonglutinous rice has relationship with storage condition and the grain varieties.