As we know propofol is popular use in the anesthesia induction with kilogram and it always cause hypotension. So we compare haemodynamic changes and drug consumption between propofol titrated administration and traditional administration for anesthesia induction.

GroupⅠreceived propofol 2 mg/kg intravenously by Fresenius pump at the speed of 250 mg/min, GroupⅡreceived propofol intravenously by Fresenius pump at the speed of 1 mg/kg/min, and observe's assessment of alertness and sedation(OAA/S) scale of the patients was titrated to 1, then changed to a maintenance dose

Inclusion Criteria:

• Patients with American Society of Anesthesiologists(ASA)Ⅰor Ⅱ and aged 18-60 yr, who were scheduled for general anesthesia.

Exclusion Criteria:

• Hypertension, Severe heart,pulmonary,brain，liver and renal dysfunction; excess obesity , predicted difficult intubation,hearing obstacles;. Allergic to propofol or its fat emulsion;addictive to sedative and other drugs.