If chemotherapy is stopped after chemotherapy, the hair may turn black. If the gray hair is caused by chemotherapy, this kind of gray hair is temporary, once the condition is relieved, the chemotherapy is over, the patient regains nutrition and physical strength, generally the hair can become black. Chemotherapy leads to endocrine dysfunction, nutritional absorption can not keep up, immunity decline, hair can not get enough nutrition, it is easy to lead to gray hair, after stopping chemotherapy, after the disappearance of various side effects of chemotherapy, it is possible to turn gray hair into black hair. Chemotherapy is an effective measure for treating tumors, and patients with tumors should take chemotherapy according to the situation. If the side effects of chemotherapy are especially big, and the patients show hair loss, leukopenia, nausea and vomiting and other serious symptoms, they should not be forced to take chemotherapy. If there are gray hair and other serious side effects of chemotherapy, we should reflect with the attending doctor in time and deal with them according to the standard.