Abstract: Objective:To investigate the difference of effect between allogeneic blood transfusion and normovolemic hemodilution autologous blood transfusion (ANH)on the immune function of pregnant women on the basis of our early research on ANH in the pregnant women received cesarean section.Method:50 pregnant women to be cesarean section were randomly divided into two groups. ANH group (group Ⅰ):Anesthesia before surgery incision after transradial bloodletting 400-600 ml, while input the same volume expansion fluid intravenously, postpartum or near the end of the birth process do autologous blood transfusion. Allogeneic blood transfusion group (Ⅱ group):According to situation during the cesarean section, 2 to 3 units of allogeneic red blood cell suspension were transfused. Respectively, in prenatal and postnatal 1 day, 5 day, natural killer (NK) cells, macrophages, IL series factors, IgG, IgM, CD3⁺, CD4⁺, and CD4⁺/CD8⁺ in peripheral blood were measured by flow cytometry.Result:① CD3⁺, CD4⁺ and CD4⁺/CD8⁺ at postnatal 1 d of the two groups significantly reduced compared with prenatal, and the decrease of group Ⅱ was more obvious compared with group Ⅰ. NK cells increased, P<0.05. CD3⁺, CD4⁺ and CD4⁺/CD8⁺ at postnatal 5 day of group Ⅱ still significantly reduced compared to prenatal, while Ⅰ group were returned to normal, and CD3⁺ and CD4⁺ of group Ⅰwere higher than those of groupⅡ, P<0.05. ②IgA and lgG at postnatal 1 d of the two groups were reduced, wihle IL 6, IL 8 and TNF-a increased, which the differences were significant, P<0.05. These indexes at postnatal 5 day were returned to normal in group Ⅰ, Ⅱ group compared with before, the differences were significant, P<0.05. IgM of the two groups did not change significantly, which the difference was not statistically significant, P>0.05. Conclusion:Autotransfusion would have little effect on maternal immune function and have no significant inhibitory effect on the cellular immune function, while allogeneic blood transfusion would have obvious suppression effect on maternal immune function. Maternal autologous blood transfusion compared with allogeneic transfusion would have obvious advantages, which should be widely applied.