Methotrexate usage includes oral, intravenous, intramuscular, and intrathecal injections, and its dosage is related to the disease and usage.Adverse effects include gastrointestinal reactions, hepatic and renal impairment. 1.Usage dosage: Oral, adults 5-10mg once a day, once a day, 1 or 2 times a week, when used for maintenance treatment of acute lymphoid leukemia, once a week, 15-20mg/dose. Intravenous injection, when used for malignant staphylococcal or chorionic epithelial carcinoma, 10～20mg/dose, once a day, 5～10 times as a course of treatment. When used for solid tumors, intravenous injection is usually 20mg/m2/dose. Intrathecal injection, when used for acute leukemia, children once a week, 20～30mg/m2 per day, adults 1～2 times a week, 10～30mg/time. Intrathecal injection, when used for meningeal leukemia, 6mg/m2 each time, once a day, 5 days as a course of treatment. 2. Adverse reactions: gastrointestinal reactions such as nausea, vomiting, abdominal pain, diarrhea, loss of appetite; hepatic impairment such as jaundice, alkaline phosphatase and other increases; renal impairment such as proteinuria, hematuria, or even uremia; bone marrow suppression such as leukocytes and platelets decreased; others such as blurred vision, headache, impaired consciousness. 3. Precautions: prohibited for patients with known hypersensitivity to this product. There is a potential risk of secondary tumors after prolonged administration of this product. This product is contraindicated in cases of extreme systemic failure, malignant fluid or concurrent infections and cardiopulmonary, hepatic or renal insufficiency. Methotrexate needs to be regulated under the guidance of a doctor, do not self-medicate.