Abstract: Objective To investigate the influence of dexmedetomidine combined with propofol on the incidence of postoperative delirium in elderly patients with intervertebral disc herniation undergoing surgery under general anesthesia and the pharmacokinetic research. Methods Total 124 cases of elderly patients with lumbar disc herniation undergoing intravenous general anesthesia in our hospital from March 2012 to March 2014 were selected as research subjects.They were divided into two groups according to the random number table method.62 cases of control group were given propofol intravenous injection of 0.5 mg/kg before anesthesia,62 cases of observation group on the basis of the control group was given intravenous injection of 1 μg/kg dexmedetomidine.Two groups of patients with postoperative delirium rate and injection of narcotic drugs after 480 at different time points and blood drug concentration and drug pharmacokinetics parameters were observed and compared. Results Postoperative 1D and postoperative 3D observation group patients with delirium incidence were significantly lower than those in the control group(P<0.05),the difference was statistically significant.Blood drug levels in the two groups were decreased rapidly,but the blood concentrations of the patients in the observation group were significantly higher than those in the control group(P<0.05),the difference was statistically significant(30 min).There was no significant difference in blood serum concentrations between the two groups at each time point after 30 min(P>0.05).The central distribution volume(Vc) and clearance rate(CL)in the observation group were significantly higher than those in the control group(P<0.05),and the difference was statistically significant. Conclusion Dexmedetomidine combined with propofol can significantly reduce the incidence of postoperative delirium in elderly patients with intervertebral disc herniation undergoing the general anesthesia through the influence on the Vc and CL pharmacokinetic parameters.