Objective To explore the reasonable dose of hydromorphone hydrochloride in the elderly patients after hip surgery. Methods 120 cases of elderly patients who underwent total hip arthroplasty in Affiliated Hospital of Jiangsu University from April 2016 to July 2016 were divided into six groups randomely,with 20 cases each group,they were 0.020,0.035,0.050,0.065,0.080 and 0.095mg/mL group,the corresponding concentrations of HYD were given to each group after surgery,blood rheology, inflammatory cytokine, VAS and Ramsay sedation scores were observed at different time points, Complications were recorded. Results One day and three days after operation,whole blood viscosity and whole blood reduced viscosity level of six groups were significantly increased (P<0.05),with the increase of the concentration of HYD,whole blood viscosity and whole blood reducing viscosity of each group decreased,compared with 0.020-0.050 mg/mL group,the 0.065-0.095 mg/mL group was lower (P<0.05).One day and three days after operation,the levels of inflammatory cytokines were increased in six groups (P<0.05),with the increase of the concentration of HYD,the level of inflammatory factors decreased,compared with 0.020-0.050 mg/mL group,the 0.065-0.095 mg/mL group was lower (P<0.05).The VAS scores of six groups were decreased in different degree with the prolongation of time, with the increase of the concentration of HYD,VAS at different time after operation decreased to some extent (P<0.05),compared with 0.020-0.035 mg/mL group,the 0.050-0.095 mg/mL group was lower (P<0.05). Ramsay sedation scores increased in 0.020-0.035mg/mL group and decreased in 0.065-0.095mg/mL group,but no significant change in 0.050mg/mL group. The incidence of adverse reactions was the lowest in the 0.050 mg/mL group. Conclusion HYD can be used for postoperative analgesia in elderly patients undergoing hip joint surgery,the concentration of HYD was correlated with the analgesic efficiency, and the recommended concentration was 0.050 mg/mL.