Abstract: Objective: To evaluate the best time of rehabilitated catheter for patients who used the patient-controlled intravenous analgesia pump after the surgery of the lower limb.Methods: The data of 180 patients were randomly selected who received the surgery of the lower limb from March 2012 to April 2013.According to the time of rehabilitated catheter,they were divided into 4 groups.The 45 cases in group Ⅰ were rehabilitated catheter in 12 hours after the surgery.The 45 cases in group Ⅱ were rehabilitated catheter in 24 hours after the surgery.The 45 cases in group Ⅲ were rehabilitated catheter in 48 hours after the surgery at the end of analgesia.The 45 cases in group Ⅳ were rehabilitated catheter in 48 hours after the surgery at the time of analgesia end and the bladder filling.The group Ⅰ and Ⅱ were not clipped the catheter before rehabilitation,and informed the importance of timely rehabilitation.The group Ⅲ and Ⅳ were clipped intermittently.They were opened when the patients have to urinate.Observing the situation of the 4 groups' urination and the positive urinary leukocyte.Results: In group Ⅰ,the positive voiding rate of the patients were significantly lower than those in group Ⅱ,Ⅲ and Ⅳ(P<0.01);the positive rate of urinary leukocyte of the patients in group Ⅲ and Ⅳ group was 20.00% and 20.22%,was higher than those in group Ⅰ and Ⅱ(P<0.05).Conclusions: To patients who used the patient-controlled intravenous analgesia pump after the surgery of the lower limb,the best time to rehabilitate catheter is 24 hours after surgery.