Abstract: In order to improve the quality traits of rice varieties, a variety named of “Koshihikari”, was radiated by 60Co γ-ray to induce mutagenesis. 72 mutants of seed storage protein were found through analyzing the content and composition of seed storage protein by SDS-PAGE and Western Blotting. These mutants had rich variations on content and composition of seed protein, and could be used as basis materials to reveal the mechanism of rice storage protein accumulation, and to develop new types of rice varieties.