Objective To investgate the effects of dexmedetomidine combined with small-dose of sufentanil on the hemodynamics during anesthesia induction in patients undergoing off-pump coronary artery bypass grafting.Methods Seventy-five ASA Ⅱ or Ⅲ and NYHA Ⅱ or Ⅲ patients aged 46-72 yr,weighing 59-86 kg,ejection fraction ≥45％,undergoing off-pump coronary artery bypass grafting,were randomly divided into 3 groups ( n =25):dexmedetomidine combined with small-dose of sufentanil group (group DS),small-dose of sufentanil group (group S1 ) and large-dose of sufentanil group (group S2 ).In group DS,dexmedetomidine 0.8 μg/kg (diluted with normal saline to 15 ml) was injected for 15 min at a rate of60 ml/h,while the same volume of normal saline were given in groups S1 and S2.Anesthesia was induced with midasolam 0.08 mg/kg and pipecuronium 0.12 mg/kg.After administration of the total dose of 1/3 midazolam and 1/8 pipecuronium,sufentanil 0.5,0.5 and 0.8μg/kg (diluted with narmalsaline to 10 ml) were injected in groups DS,S1 and S2 respectively.Then the rest of midazolam was injected.When BIS value ≤ 75,the rest of pipecuronium was injected.When BIS value ≤ 55,the patients were tracheal intubated and mechanically ventilated.PETCO2 was maintained at 30-35 mm Hg.The adverse ardiovascular events (hypertension,hypotension,tachycardia and bradycardia) and drugs intervention were recorded during anesthesia induction.Results Compared with group S2,the incidence of hypertension and tachycardia was significantly increased in group S1,the incidence of hypotension decreased in groups S1 and DS,the incidence of drug intervention decreased in group DS (P ＜ 0.05).Compared with group S1,the incidence of hypertension,hypotension and tachycardia was significantly decreased,the incidence of bradycardia increased,theincidence of drug intervention decreased in group DS (P ＜ 0.05).Conclusion Dexmedetomidine (0.8 μg/kg) combined with small-dose of sufentanil (0.5 μg/kg) is beneficial for keep the stable of hemodynamics during anesthesia induction in patients undergoing off-pump coronary artery bypass grafting.