Inclusion Criteria:  Twenty to eighty-year-old. ASA class I-III. Patients undergoing elective craniotomy for primary brain tumors under general anesthesia.  Exclusion Criteria:  Severe mental disorder Poor liver function Pregnant or lactating women Morbidly obese Allergy to any of the drugs used in this study Recurrent tumor or repeat surgery Biopsy cases Incomplete outcome-data Palliative treatment after surgery simultaneous treatment of other malignancies Emergency surgery Presence of other malignant tumors Combined propofol and inhalation anesthesia or other anesthetics, such as ketamine or dexmedetomidine Diagnosed as benign brain tumor cerebellum tumor and pituitary gland tumor.