It is intended to provide a screening system for a centrally acting drug transported across the blood-brain barrier, a drug acting on the blood-brain barrier itself, or a drug transferred into the brain without being expected to centrally act. Moreover, another object of the present invention is to achieve pathogenesis analysis study or the screening in a diseased state by applying various diseased environments to this screening system. The present invention provides an in-vitro model of blood-brain barrier obtained by using a three-dimensional culture apparatus comprising: a culture solution; a plate holding the culture solution; and a filter immersed in the culture solution and placed in no contact with the inside bottom of the plate, the filter having plural pores of 0.35 to 0.45 μm in diameter, and by comprising: seeding primary cultured brain capillary endothelial cells onto the upper surface of the filter; seeding primary cultured brain pericytes onto the under surface of the filter; seeding primary cultured astrocytes onto the inside surface of the plate; and coculturing these cells in a normal culture solution.