Objective To investigate the effects of ovarian induction with raloxifene(RAL)versus clomi-phene citrate(CC)on the endometrial receptivity in mouse endometrium during perimplantation period. Methods 48 female Kun-ming mouse were randomly divided into four groups in equal number:RAL 240 mg group,RAL 180 mg group,CC group,natural conception group(NC),all treated with ovulation induction after drug administration.Successfully mated female mouse were killed,and uterus samples were collected for HE stain-ing and immunohistochemistry. Results HE staining showed that the endometrial morphology in the RAL 180 mg group and RAL 240 mg group and NC group were better than that of CC group.The expressions of COX-2 and LP-AR3 in the RAL 180 mg group and RAL 240 mg group were similar to NC group,without significant difference among the three groups(P > 0.05). But in the CC group,it was statistically significantly lower than other three groups(P<0.05),indicating ovarian induction with RAL did not decrease the expressions of COX-2 and LPAR3 in endometrium. Conclusion The mechanism of ovulation induction with RAL is similar to CC,but RAL has fewer adverse effects on the endometrial receptivity compared with CC.