Abstract: Objective To investigate effect of vaginal delivery analgesia with low-concentration ropivacaine on maternal fever and pyretic cytokine. Methods A total of 120 primiparas admitted to our hospital were selected as research objects and divided into three groups according to random number table method. Groups Ⅰ, Ⅱ and Ⅲ were given ropivacaine at concentrations of 0.075%, 0.100% and 0.125%ropivacaine, respectively, for delivery analgesia. The tympanic membrane temperature, duration of labor and analgesia, serum pyretic cytokine, maternal fever rate, neonatal body index and Apgar score were compared among the three groups. Results There were no significant differences in tympanic membrane temperature after 3 hours of analgesia, immediately after delivery and at 2 hours after delivery compared to analgesia before between the three groups(P>0.05). The tympanic membrane temperature at 4 and 5 hours after analgesia showed significant differences than analgesia before(P<0.05). There was no significant difference in time of the first and third stages of labor in the three groups(P>0.05); the time of the second stage labor and time of analgesia in group Ⅰ were shorter than that in group Ⅱ, and group Ⅱwas shorter than group Ⅲ in above indicators(P<0.05); the fever rate in group Ⅲ was higher than that in group Ⅰ and group Ⅱ, and the - difference were statistically significant(P<0.05). There was no significant difference in the levels of serum febrile factors among the three groups before analgesia, immediately after delivery and 2 hours after delivery(P>0.05). Compared with before analgesia, the levels of interleukin-6(IL-6), interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)in the three groups immediately after delivery and 2 hours after delivery were all increased, and the level of serum pyrogenic factor increased significantly immediately after delivery(P<0.05). There were no significant differences in neonatal body mass and Apgar scores at 1 and 5 min between the three groups(P>0.05). Conclusion The fever rate of ropivacaine analgesia at a low concentration for parturients is low, but there is no significant effects of different concentrations of ropivacaine on the level of pyretic cytokines.