An objective of the present invention is to provide promoters having seed-specific promoter activity, and methods of expressing foreign proteins in seeds. In particular, a seed specific promoter from the rice glutelin GluB-4 gene is disclosed. The present inventors isolated the promoters of a number of genes that are expressed in rice seeds, constructed binary vectors in which each promoter is inserted upstream of the GUS reporter gene, and transformed rice using the Agrobacterium method. The inventors then used GUS expression level as an index to examine the site of expression, the expression pattern during seed maturation, and the level of expression in seeds for each promoter. They thus discovered promoters with activity specific to a particular site in seeds, and with higher activity than constitutive promoters and known seed-specific promoters.