A method that uses the peak height of endothelium cells in a test substance as an indicator of vascular hyperpermeability regulation action in the endothelium cells, and which comprises: a step in which the test substance is brought in contact with the endothelium cells; a step in which a drug that exacerbates vascular permeability in endothelium cells is brought in contact with the endothelium cells; and a step in which the peak height of the endothelium cells is measured.
