【Abstract】 Objective To discuss the expression and clinical significance of macrophage migration inhibitory factor (MIF) and Toll like receptor 4 (TLR4) in patients with recurrent spontaneous abortion. Methods 48 patients with recurrent spontaneous abortion were selected as the reflow group from March 2016 to March 2018 in The Second Affiliated Hospital of Xi'an Jiao Tong University. 48 normal pregnant women with induced abortion were selected as control group at the same time. The expression of MIF and TLR4 in the decidua tissue was detected by immunohistochemical streptomyces avidin peroxidase linked method. The serum MIF level was detected by enzymelinked immunosorbent assay method. The MIF and TLR4 levels were compared between the two groups. Results The pathological HE staining of decidua in control group showed clear and complete. The villous structure in reflow group was structural defect, edema, degeneration, infiltration of inflammatory cells and degeneration, necrosis and hyperplasia of trophoblast cells. The decidua tissue and serum MIF level in the reflow group were significantly lower than those in the control group. The decidua tissue TLR4 level in the reflow group was significantly higher than that in the control group (P＜0.05). The Pearson correlation analysis results showed that the decidua tissue and serum MIF level were negatively correlated withTLR4 (P＜0.05). Conclusions The decidua tissue and serum MIF and TLR4 may be involved in the onset of recurrent abortion, and the low expression of MIF and high expression of TLR4 may be the important index for evaluating the occurrence of recurrent spontaneous abortion.