[Problem] To improve the conception chance of semen after cryopreservation by improving conventional straws for artificial insemination. [Solution] A straw for cryopreservation is produced by introducing a partitioning layer into a straw for artificial insemination to separate layers, thereby forming a semen storage layer comprising an aqueous solution containing semen and an anti-freeze agent on one side and a dilution layer containing no anti-freeze agent on the other side, wherein a dilution solution comprising an aqueous solution containing tris(hydroxymethyl aminomethane), citric acid, glucose and sodium chloride is used in the dilution layer.
