Abstract: The present invention relates to a composition for use in prevention or treatment of a vascular-related disease, particularly used for angiogenesis inhibition, tumor growth inhibition or tumor metastasis inhibition, or immunostimulation, which comprises glutamic acid or derivatives thereof, preferably glutamic acid is anhydrous glutamic acid represented by Formula (1) or pyroglutamic acid, and a pharmaceutically acceptable carrier or an edible carrier, and a method of preventing or treating a vascular-related disease.