To provide a promoter having seed-specific activity and to provide a method for expressing a foreign protein in a seed.

A plurality of promoters of rice seed expression genes are isolated; a binary vector is prepared by inserting each promoter to the upstream of GUS reporter gene and rice is transformed by an Agrobacterium method. An expression site by each promoter, an expression in a seed maturation process and an expression strength in a seed are examined by using an expression amount of GUS as an index and thereby a promoter that has specific expression activity at a specific site of seed and higher activity than those of a constant promoter and a known seed-specific promoter has been found.