Abstract: Objective To investigate the effect of labor analgesia on inflammatory factors, complement and T lymphocytes (CD3⁺, CD4⁺, CD4⁺/CD8⁺) of parturient, and analyze its effect on immune function. Methods A total of 278 pregnant women were selected in department of obstetrics and gynecology of affiliated hospital of medical college of Ningbo university from February 2015 to February 2017, those pregnant women were divided into observation group (167 cases) and control group (111 cases) according to whether they were willing to receive labor analgesia. The observation group was treated with epidural labor analgesia, the control group did not take any analgesic measures. At the time of the cervix was open to 2-3 cm (T1), the cervix was full opened (T2), after the childbirth (T3) and 24 hours after delivery (T4), the visual analogue scale (VAS) scores, the levels of IL-1β, IL-6, hypersensitive C-reactive protein (hs-CRP), complement C3, complement C4, CD3⁺, CD4⁺, CD4⁺/CD8⁺, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), duration of labor and 1 min Apgar score of newborn in the two groups were observed. Results Compared with T1, the VAS scores of other time (T2-T4) in observation group decreased significantly (all P<0.05), and the VAS scores of observation group were significantly lower than those of control group (all P<0.05). Compared with T1, the levels of IL-1β, IL-6 and hs-CRP of other time (T2-T4) in two groups increased significantly (all P<0.05), and the levels of observation group were significantly lower than those of control group (all P<0.05). Compared with T1, the levels of complement C3 and C4 of other time (T2-T4) in two groups decreased significantly (all P<0.05), and the levels of observation group were significantly higher than those of control group (all P<0.05). Compared with T1, the levels of CD3⁺, CD4⁺, CD4⁺/CD8⁺ of other time (T2-T4) in two groups decreased significantly (all P<0.05), and the levels of observation group was significantly higher than those of control group (all P<0.05). There was no significant difference in SBP, DBP and HR between the two groups at each time (all P>0.05); There was no significant difference in the time of first, second and third labor and the Apgar score of 1 min in neonates between the two groups (all P>0.05). Conclusion Labor analgesia can significantly reduce pain and inflammation of parturient, improve the levels of complement and T lymphocytes, further improve the immune function.