To explore the effects of Erbu Zhuyu Decoction on cyclooxygenase-2 (COX-2) and peroxisome proliferators-activated receptors δ (PPARδ) expression in mouse model of embryo implantation dysfunction.Methods:A C57 pregnant mice were randomly divided into a blank group,a model group,an aspirin group,a progynova group,a high-dose,a middle-dose and a low-dose groups,with 8 cases in each group.Embryo implantation dysfunction model was built with indomethacin.Mice in each group were administrated with corresponding medicine.The uteri were excised on 5th day of pregnancy to determine the expression of COX-2 and PPARδ.Results:The uteri in model group showed pale and slender.Beads changed little,and the distribution was sparse and uneven.Compared with the model group,the uterus of mice in each treatment group was rosier,with bead-like changes,and the distribution of beads was increased and uneven.The expression of COX-2 and PPARδ protein in the model group was lower than that in the blank group (P<0.05); the expression of COX-2 protein in each treatment group was higher than that in the model group (all P<0.05).The expression of PPARδ mRNA in the low-dose and high-dose groups of Erbu Zhuyu Decoction was significantly higher than that of the model group and estradiol valerate tablets group (P<0.05),and the expression of PPARδ mRNA in the aspirin group was higher than that of the middle-dose Erbu Zhuyu group (P<0.05).The expression of PPARδ protein in each dose group of Erbu Zhuyu was higher than that of the model group (P<0.01),and the middle dose group was higher than that of estradiol valerate tablets group and aspirin group (P<0.05).Conclusion:Erbu Zhuyu Decoction could improve endometrial receptivity by regulating COX-2 and PPARδ expression,improve the receptivity of the endometrium and be conducive to embryo implantation.