Objective To dertermine the effective concentration of remimazolam required to prevent cardiovascular response to tracheal intubation in elderly patients. Methods According to the random number table method, the elderly patients who were undergo general anesthesia were selected. The first patient was given remimazolam 0.16 mg/kg. The dose of remimazolam for the next patient was used the Biased Coin Design (BCD) method and based on the cardiovascular response to tracheal intubation in the previous patient. The cardiovascular response to tracheal intubation, the number of patients with Observer's Assessment of Alertness/Sedation (OAA/S)>1 and Bispectral Index (BIS)>65, and the occurrence of hypotension, bradycardia and injection pain were recorded. According to the above observation results, the median effect concentration (EC50) and effect concentration 90 (EC90) of remimazolam to prevent cardiovascular response to tracheal intubation was analyzed and calculated. Results The EC50 and EC90 of remimazolam to prevent cardiovascular response during tracheal intubation was 0.156 (0.093‒0.167) mg/kg and 0.176 (0.150‒0.254) mg/kg, respectively. No patient OAA/S>1 and BIS>65 were observed in the patients. There were no hypotension, bradycardia or injection pain were observed in this test. Conclusions The EC90 of remimazolam to prevent cardiovascular response in elderly patients during tracheal intubation was 0.176 mg/kg.