The invention relates to an endosperm specific high-expression promoter pENP4 and application thereof. The promoter is capable of realizing specific high expression in endosperm and instructing target genes to realize specific high expression in the endosperm but realize low expression or no expression in other tissues of plants. The invention further provides a plant expression vector, an expression box containing the promoter, a method for acquiring corresponding host bacteria and transformants and application of the method to plant genetic engineering. The promoter has theoretical and practical significances to related researches on rice endosperm. The endosperm specific high-expression promoter pENP4 has a bright application and market prospect in the agricultural field and can be used with genes having an endosperm improving function to improve all aspects of characters of the rice endosperm.