Objective: To investigate the effect of pretreatment with dexmedetomidine and dezocine on rocuronium injection pain.Methods: 120 cases of patients under general anaesthetic for elective surgery were randomly divided into 4 groups (n=30): control group (group C), dexmedetomidine group (group Y), dezocine group (group D) and dexmedetomidine and dezocine unions group (group L). They received normal saline 5 ml, dexmedetomidine 0.5μg/kg, dezocine 0.1 mg/kg, and dexmedetomidine 0.5 μg/kg combined with dezocine 0.1mg/kg respectively. The incidences of injection pain and fentanyl-induced cough were observed and the changes of blood pressure (BP) and heart rates (HR) were monitored and recorded.Results: Compared with group C, the incidences of injection pain and fentanyl-induction cough in group Y, group D, and group L significantly decreased (P＜0.05); the incidences of injection pain and fentanyl-induction cough in group L were lower than those in group Y and group D (P＜0.05). After anesthesia induction, HR and the amplitude of mean arterial pressure (MAP) in group Y and L were significantly slower than those in group C and D (P＜0.05).Conclusion: Pre-injection of dexmedetomidine and dezocine before anesthesia induction can significantly reduce rocuronium injection pain, promote the stability of anesthesia induction circulation, and reduce the incidence of fentanyl-induction cough.