Objective:To observe the effects of epidural labor analgesia during latency period on factors related to labor process.Methods:A total of 120 single fetus cephalic presentation primiparas,aged from 22 to 35,were enrolled and randomly divided into group undergoing epidural labor analgesia during latency period (group Q),group undergoing epidural labor anal-gesia during active period (group H),and control group without epidural labor analgesia (group C).Duration of each labor pe-riod,pain score and amount of bleed were compared among the groups.Venous blood was collected for determination of inter-leukin (IL-6,IL-8)and tumor necrosis factor-α(TNF-α)levels before latent phase of labor or before starting infusion of oxyto-cin (time 1),2 h after delivery (time 2)and 24 h after delivery (time 3).Results:The second stage of labor in group Q or group H was longer than that in group C and the difference was statistically significant(P <0.05).However,there was no sta-tistical significance regarding other stages of labor among the three groups (P >0.05).There was no statistical significance re-garding IL-6,IL-8 and TNF-αlevels among the three groups at each of the 3 time points above (P >0.05).Conclusions:Epi-dural labor analgesia during latency period or active period could prolong the second stage of labor to different degree,but it had little effect on the entire labor process.Epidural labor analgesia had no significant effect on serum cytokines related to the birth process.Changing the time point of epidural labor analgesia from active period to latency period could improve maternal com-fort,so that it is worthy of clinical application.