It is an object of the present invention to provide a method for efficient differentiation into blood cells. Specifically, in the present invention, when blood cells are produced from pluripotent stem cells such as ES cells or iPS cells in vitro, the cells are cultured under a low oxygen partial pressure to increase the efficiency of differentiating the pluripotent stem cells into hematopoietic progenitor cells, erythroid progenitor cells, and the like, so as to increase the number of finally obtained, desired blood cells.
