The composition and distribution of seed storage proteins are important factors for eating quality such as grain flavor and quality in rice (OryzasativaL.) Rice protein disulfide isomerase (OsPDI) and binding protein (OsBIP) regulate synthesis, stability and sorting of storage proteins. We thus have tried to develop a marker protein for selection of rice cultivars which have different eating quality. Immunoblot analysis revealed that protein levels of OsPDI and OsBIP have no direct correlation with eating quality, suggesting that they may indirectly participate in control of eating quality through their-interacting partners or other regulatory mechanism.