To find the threshold dose level at which flavor change could be detected in cooked rice, organoleptic test and measurement of cooking quality were conducted on rice treated with various levels of cathode ray. No significant difference in water absorption, swelling volume, and intensity of iodine-starch coloration of soluble fraction of cooked rice was recognized between control and irradiated samples both immediately and eight months after irradiation up to the dose of 60Krad. Off-flavor developed immediately after the irradiation of 30Krad or more, and the rice irradiated at 60Krad was of disagreeable odor, taste, and appearance. However, after the storage of eight months, no significant difference in such characteristics was found among the irradiated samples. Organoleptic quality change by irradiation of 30Krad became undetectable after storage of four months. By measurement of physical properties of cooked rice with Texturometer, significant negative correlations were found between the dose level and hardness, and gumminess, repectively.