Blood cell morphology examination is performed by drawing peripheral blood from a patient to make slides, which are then stained and the morphology of various blood cells is observed under a microscope, thus providing useful information for the diagnosis of clinical disease. If a large number of immature infantile cells are found in the peripheral blood through morphological examination, it is highly suspected that the patient has leukemia and a bone marrow aspiration is often required to further confirm the diagnosis. If a routine morphological examination reveals a significant decrease in the number of various blood cells in the peripheral blood, the patient should be considered to have aplastic anemia, and a bone marrow biopsy is often required to confirm the diagnosis. If a large number of fragmented red blood cells are found in the morphological examination of blood cells, the most common disease at this time is hemolytic anemia.