The present invention relates to a stem cell composition for venous administration, the composition containing between 1x10 7 and 5x10 8 cells/ml of stem cells present as single cells and having a diameter of between 10 and 20 µm. The present invention makes it possible to provide a stem cell composition suitable for venous administration, and makes it possible to relatively efficiently enhance the efficacy with which vascularly administered stem cells stably reach target tissue and exhibit an action, and can therefore dramatically increase the efficacy of cell therapy using stem cells.
