To investigate the effects and mechanism of Baicalin on recurrent abortion mice.Methods:Construction of recurrent abortion mouse was based on Clark's classic model, and the mice with recurrent abortion successfully constructed were randomly divided into a model group and a test group with 10 mouse in each group.Meanwhile, normal pregnant mice with 10 mouse were as control the group.On the second day of pregnancy, 0.4 mL/mg baicalin was given by gavage in the test group, and 0.9% NaCl was given by gavage in the model group and the control group once a day for 7 days.Enzyme linked immunosorbent assay were used to detect the levels of hormones in serum and content of inflammatory factors in maternal-fetal interface; immunohistochemistry was used to detect the distribution of macrophages in mouse uterus; Western blotting was used to detect the expression of activated toll like receptor 4 (TLR4), nuclear factorκ B (NF-κB) and myeloid differentiation factor 88 (MyD88) protein expression in mouse uterus.Results:TNF-α/IL-4 were (2.78±0.36), (4.89±0.58) and (3.39±0.34) in the control group, model group and test group, and E2 were (25.16±3.69), (17.56±4.52) and (22.36±4.16) ng/L in the serum.The relative expressions of CD14 protein in the mouse uterus were (9.36±2.34), (68.12±13.52) and (33.46±2.85), respectively.The expressions of TLR4 protein expressions were (0.23±0.02), (1.25±0.33) and (0.45±0.12).NF-κB protein expressions were (0.59±0.14), (1.52±0.36) and (0.78±0.25), MyD88 protein expressions were (0.63±0.24), (2.34±0.22) and (1.26±0.31), all of which were statistically significant (P<0.05).Conclusion:Baicalin can improve the estrogen level of mouse with recurrent abortion, reduce the inflammatory state of the maternal fetal interface.It is related to the inhibition of intimal macrophage infiltration and the regulation of TLR4-NFκB signaling pathway activity..