After rice seed was irradiated, the embryonal structure (structure of embryo bud and radicle) was affected by -ray. The result revealed that the outline and venations of embryo and radicle were unclear with the increasing dose. These changes of embryonal structure caused by increasing irradiation dose were due to the increasing breakage degree of embryo (including embryo bud and radicle) cells. The influence of γ-ray irradiation on the structure of radicle was more significant than that of embryo. The results were confirmed by a germination experiment, which showed that the lengths of buds of irradiated rice were diminished, the roots of irradiated rice were found to disappeare, and the germination of irradiated rice was 0%. After long-term storage, the germination rate of irradiated rice seed increased and that of some irradiated samples were found to reach to comparatively high values after different storage time.