Abstract: Objective:To compare the postoperative analgesia effects of dezocine at different time points on patients treated with radical prostatectomMethods:Fifty patients scheduled for the radical prostatectomy were randomly divided into Ⅰ group and Ⅱ group.The 0.05mg/kg of dezocine was intravenously injected in Ⅰ group at 10 min before anesthesia induction,the 0.05mg/kg of dezocine was intravenously injected in Ⅱ group at 10 min before the end of operation.The total and effective compression number of PCA after 12 and 24 hours of operation,and the Visual analog scale(VAS) scores and Bruggman comfort scale(BCS) scores after 2,4,6,12 and 24 hours of operation were observed.The postoperative adverse reactions in two groups were recorded.Results:The times of the total and effective compression of PCA after 12 and 24 hours of operation and use of fentanyl in Ⅰ group were lower than those in Ⅱ group(P<0.05 to P<0.01).The VAS scores after 2,4,6 and 12 hours of operation in Ⅰ group were lower than those in Ⅱ group,but the results of BCS scores were higher than the opposite(P<0.01).The difference of the incidence of adverse reaction was not statistical significance(P>0.05).Conclusions:The postoperative analgesia effects of dezocine combined with fentanyl PCA before anesthesia induction are good,which can decrease the use dose,which is little adverse reaction.