[Abstract] Objective To investigate the effects of epidural analgesia with 0.075% or 0.1% ropivacaine on the maternal fever and interleukin-6 during labor. Methods eighty healthy term nulliparas were randomly assigned to receive epidural analgesia with either 0.1% ropivacaine or 0.075% ropivacaine. Epidural analgesia was initiated with 10 ml increment of the randomized solution and 0.5 μg/ml sufentanyl after a negative test dose of 5 ml of 1.5% lidocaine, and maintained with 7 ml bolus doses of the abovementioned mixed analgesics every 30 minutes by the patient-controlled epidural analgesia. The measurements included the incidence of maternal fever, interleukin-6 in maternal and cord venous blood, labor events and neonatal outcomes. Results Epidural analgesia with 0.075% ropivacaine could significantly lower the incidence of maternal fever than the one with 0.1% ropivacaine. Interleukin-6 rose during labor in all groups. There was no intergroup interleukin-6 change in maternal or cord serum in group H versus group L or febrile versus afebrile. Conclusion Epidural analgesia with 0.075% ropivacaine could significantly lower the incidence of maternal fever than the one with 0.1% ropivacaine. This effect is not related with interleukin-6.