Provided is a method for controlling the propagation and differentiation of hematopoietic stem cells derived from umbilical cord blood. The method displays superior safety for propagation by culturing of the hematopoietic stem cells. The hematopoietic stem cells are seeded in a medium containing the ultrasound-treated liquid component of umbilical cord blood. Propagation and differentiation of umbilical cord blood hematopoietic stem cells can be suppressed as long as operations are performed in the presence of the ultrasound-treated liquid component of umbilical cord blood. On the other hand, propagation of umbilical cord blood hematopoietic stem cells can be promoted by seeding the hematopoietic stem cells in a medium containing the liquid component of umbilical cord blood that has not been subjected to ultrasound treatment. Thus, it is possible to arbitrarily control propagation and differentiation and promote propagation of umbilical cord blood hematopoietic stem cells by using serum derived from umbilical cord blood.
