A liquid for cryopreserving a cell and a liquid for administration of a mammalian cell capable of cryopreserving a mammalian cell and effectively suppressing cell death after thawing, and a method for cryopreserving a mammalian cell using the cell cryopreservation liquid. The liquid is an isotonic solution that includes 2.0 to 6.0% (w/v) of trehalose or a derivative thereof, or a salt of the trehalose or the derivative, 4.0 to 7.0% (w/v) of dextran or a derivative thereof, or a salt of the dextran or the derivative, and DMSO or glycerin.