To provide cryopreservation liquids for biological samples with high cell viability, to provide cryopreservation methods for biological samples, and to provide methods for stably storing biological samples for a long period of time.SOLUTION: Provided are a cryopreservation liquid for biological samples, which has a viscosity average molecular weight of more than 3000 and 500000 or less in a solvent, and contains a polysaccharide containing a six-membered ring structure in its main chain or a salt thereof; a cryopreservation method comprising including a biological sample in a cryopreservation liquid containing a polysaccharide or a salt thereof; a method for storing a biological sample; and a cryopreservation agent for biological samples consisting of a polysaccharide or a salt thereof.SELECTED DRAWING: None
