The objects of the present invention are to solve low test efficiency and low accuracy which are problems encountered in the conventional methods for testing myelotoxicity of a drug by observing smears. To this end, markers for discriminating and identifying hematopoietic stem cells and blood cells at various differentiation stages in bone marrow are identified. From this point of view, cell surface antigens are specified. Thus, it is found that the myelotoxicity of a drug can be evaluated with a high efficiency at a high accuracy by using flow cytometry to analyze for a change in the quantity of bone marrow-derived cells expressing the cell surface antigens after administration of the drug to an animal.