Abstract: Objective To investigate the effect of etomidate on the hemodynamics in elderly and shock patients during general anesthesia induction. Methods Totally 100 elderly patients or patients with hemorrhagic shock (ASAⅡ -Ⅲ) undergoing surgery were studied. Anesthesia was induced with 4 μg/kg of fentanyl, 0.1 mg/kg of vecuronium and 0.2-0.3 mg/kg of etomidate, and the mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV), stroke index (SI), cardiac output (CO), cardiac index (CI), cardiac acceleration index (ACI), left cardiac work (LCW), and left cardiac work index (LCWI) were recorded using thoracic electrical bioimpedance (TEB) hemodynamic monitoring system before induction and at 1, 2 and 3 min after etomidate injection as well as at 3 min after intubation. Results After etomidate injection, MAP, HR, SV, SI, CO, CI, ACI, LCW and LCWI were decreased significantly as compared with those before induction (P<0.05). MAP, HR, CO, CI and ACI at 3 min after intubation were higher than those before induction (P<0.05), and the other indices resumed the baseline level. The amplitudes of such changes in the recorded indices was below 20% of the baseline level in the course of anesthesia induction. Conclusion Cardiovascular hemodynamics may vary slightly during the course of induction with etomidate, which is an ideal drug for anesthesia induction for elderly or shock patients with unstable hemodynamics.