To provide a plastic container superior in cold resistance and practical usability by using a composition having a crosslinked structure, with respect to the container made of the composition of a polymer mainly composed of ethylene, and syndiotactic 1,2-polybutadiene.

This container for cryopreservation is composed of a composition of (A) a polymer mainly composed of ethylene, and (B) syndiotactic 1,2- polybutadiene, and the composition has a crosslinked structure. According to this constitution, (1) the crosslinking reaction easily occurs by the existence of (B) having double bond, and the dose for the irradiation of radiation can be reduced. Further the crosslinking by the irradiation of the light (UV) is also available. (2) As the affinity (dispersibility) of (B) is proper, the superior cold resistance in comparison with that of a crosslinked matter of a single polymer, can be obtained. An important point is that the composition of (A) and (B) has the crosslinked structure. The cold resistance is deteriorated when the crosslinked structure is not provided.