Abstract: Objective To observe the clinical efficacy of ketorolac tromethamine(KT)preemptive analgesia combined with postoperative patient-controlled intravenous analgesia(PCIA)in total knee replacement(TKR). Methods A total of 84 TKR patients were randomly divided into control group and observation group. The control group(n=42)was only given postoperative PCIA, while observation group(n=42)was given KT preemptive analgesia combined with postoperative PCIA. The postoperative time to first getting out of bed, number of analgesia pump presses within 48 h after surgery, scores of Visual Analogue Scale(VAS)at 24 h and 48 h after surgery, serum pro-inflammatory factors ［tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), interleukin-8(IL-8)］ and serum stress indexes ［serum cortisol(Cor), adrenocortical hormone(ACTH)］, and occurrence of adverse reactions during treatment were compared between the two groups. Results The postoperative time to first getting out of bed in observation group was earlier, and number of analgesia pump presses within 48 h after surgery was significantly less than that in control group(P<0.05). At 24 h and 48 h after surgery, VAS scores, levels of TNF-α, IL-6, IL-8, Cor and ACTH in the observation group were significantly lower than those in control group(P<0.05). During postoperative analgesia, the two groups occurred nausea and vomiting in one case. There was no significant difference in incidence of adverse reactions between the two groups(P>0.05). Conclusion KT preemptive analgesia combined with postoperative PCIA for TKR can shorten postoperative time to first getting out of bed, - reduce number of analgesia pump presses within 48 h after surgery, effectively alleviate pain, inflammatory reactions and stress response after TKR, and it has higher safety.