Inclusion Criteria:  Ages ranged from 65 to 80 ASA I~II patients undergoing elective general anesthesia BMI 18.5-30.0  Exclusion Criteria:  refusal of patients emergency surgery, neurological or mental disorders , Liver and kidney dysfunction previous allergy to ephedrine and phenylephrine heart disease history, such as pacemaker implantation, unstable angina, congestive heart failure, Heart valve disease nerve, digestive, endocrine system diseases, and affect intravascular Fluid volume or balance diseases (such as inflammatory diseases or gastrointestinal obstructive diseases) emergency surgery malignant tumors tachycardia (HR>100) bradycardia ( HR<50) intraoperative hypotension that is difficult to correct with ephedrine and phenylephrine use of other vasoactive drugs. surgery time <40 min