(1) A method for the preparation of neural stem cells comprising culturing marrow cells in the presence of an immunosuppressing agent or serum collected from a human or animal suffering from cerebral infarction (or, in place of the serum, a cytokine such as a chemokine); (2) a method for the preparation of neural stem cells comprising culturing marrow cells collected from a human or animal suffering from cerebral infarction in the presence of an immunosuppressing agent; and the like. These methods are useful for the nerve regenerative therapy or the development of such a therapy.