An object of the present invention is to provide a cell structure for brain damage treatment which does not contain glutaraldehyde and in which it is possible to exhibit a sufficient effect of treating brain damage, a production method thereof, and a brain damage treatment agent. According to the present invention, there is provided a cell structure for brain damage treatment which contains biocompatible macromolecular blocks and at least one kind of cell and in which a plurality of the biocompatible macromolecular blocks are disposed in gaps between a plurality of the cells, in which the tap density of the biocompatible macromolecular block is 10 mg/cm3 to 500 mg/cm3 or a value obtained by dividing a square root of a cross-sectional area in a two-dimensional cross-sectional image of the biocompatible macromolecular block by a peripheral length is 0.01 to 0.13.