Some people have normal white blood cells after chemotherapy, probably because there is no myelosuppression or the myelosuppression is in a situation where the body can compensate. The reason for low white blood cells after chemotherapy is that chemotherapeutic drugs can damage the hematopoietic function of the bone marrow, and the inhibition of the hematopoietic function of the bone marrow leads to low hematopoietic function of the bone marrow, which results in a decrease in white blood cells. However, not all people will have bone marrow suppression, some patients have strong bone marrow function compensation ability after chemotherapy, active bone marrow proliferation, and the number of white blood cells is normal. Different drugs have different inhibitory effects on the bone marrow, and the same chemotherapeutic drugs have different inhibitory effects on the bone marrow of different people, therefore, not all people will experience a decrease in white blood cells after chemotherapy. If a decrease in white blood cells occurs, white blood-boosting drugs need to be applied under the guidance of a doctor if necessary.