Objective:To explore the mechanism of Yiqi Huoxue Prescription in regulating ferroptosis in endometriosis through MIR-143-3P targeting.Methods:The adherent purification method was used to culture in vitro the isolated endometrial tissue from patients with endometriosis, both in situ and ectopic. The CCK-8 assay was used to detect cell viability. ELISA was used to detect the levels of Fe 2+, MDA, and reduced GSH, and qPCR was used to detect the mRNA expressions of GPX4 and MIR-143-3P. Female SD rats were randomly divided into five groups: sham-operation group, model group, and Yiqi Huoxue Prescription low -, medium -, high - dosage groups, with 8 rats in each group. An endometriosis rat model was established through surgery. Yiqi Huoxue Prescription low-, medium-, and high- dosage groups were administered the solution at dosages of 6.25, 12.5, and 25 g/kg respectively. The sham-operation group and the model group were given the same volume of normal saline. Administration was done twice a day for four consecutive weeks. The volume and weight of ectopic endometrial lesions in rats were measured. HE staining was used to observe pathological changes in the lesions. Levels of Fe 2+, MDA, and GSH were determined. PCR was used to detect GPX4 and MIR-143-3P mRNA levels, and Western blot analysis was used to assess the protein expressions of solute carrier family 7 member 11 (SLC7A11) and GPX4. Results:Compared with the eutopic endometrial cells, the viability of ectopic endometrial cells was enhanced, and the levels of Fe 2+, MDA, and MIR-143-3P mRNA decreased ( P<0.01), while the levels of GSH and GPX4 mRNA increased ( P<0.01). Compared with the model group, the volume and weight of ectopic lesions were reduced in Yiqi Huoxue Prescription high-dosage group ( P<0.01), levels of MIR-143-3P, Fe 2+, and MDA in ectopic lesions were elevated ( P<0.05 or P<0.01), and GSH and GPX4 mRNA levels, as well as the expression levels of SLC7A11 and GPX4 in ectopic lesions, decreased ( P<0.05 or P<0.01). Conclusion:MIR-143-3P is involved in the regulation of ferroptosis in ectopic endometrial cells, and high-dosage Yiqi Huoxue Prescription may promote ferroptosis in ectopic endometrial cells by up-regulating the expression of MIR-143-3P, thereby reducing the ectopic endometrial lesions in endometriosis rats.