Objective Compared with the simple mechanical injury method and the artificial abortion mechanical injury method, to explore the animal model which is more in line with the clinical etiology and disease characteristics of endometrial injury,and to explore the reasons why intrauterine operation during pregnancy is more likely to cause injury. Methods 42 female rats were randomly divided into 3 groups: Sham operation group(N=6) , simple mechanical injury group(N=18), and artificial abortion injury group(N=18), except for the Group Sham, the other two groups were divided into 3 subgroups, which were taken in the first, second and third estrous period after operation. The histopathology changes of endometrium were observed by HE staining, the degree of endometrial fibrosis was observed by Masson staining, and the expression of CD31 and LIF in rat uterine tissue was detected by immunohistochemistry The expression of CD68 in endometrium was detected by immunofluorescence. Serum levels of inflammatory factors and hormones were measured by ELISA, and the expression of CD68, CD86 and TGF-β in endometrium was detected by Western blot.Results (1) in the third estrous phase after surgery, the pathological changes of the uterus in Group S were small, and the changes of endometrial thickness, epithelial cells and macrophages were not significant, there was no significant difference in the level of inflammation between the Group S and Group Sham. Only the level of fibrosis and the ability of vascular regeneration were consistent with the clinical characteristics of endometrial injury. However, in the Group A, the endometrium became thinner, the number of glands decreased, the luminal epithelial cells decreased significantly, the expression of macrophages increased and was accompanied by obvious inflammatory response, and the level of uterine fibrosis increased significantly, the ability of vascular regeneration was decreased. Four dimensions were in line with the clinical characteristics. (2) the level of endometrial fibrosis increased with the increase of injury time, and the level of serum inflammatory factors decreased with the increase of injury time, however, the level of inflammatory factors decreased more slowly and the inflammatory reaction lasted longer in rats with artificial abortion and mechanical injury.Conclusion the artificial abortion injury model is more in line with the current understanding of the clinical etiology and disease characteristics of human endometrial injury, the reason why the uterine cavity operation during pregnancy is more vulnerable to injury may be related to the sustained high expression of macrophages, which leads to the chronic inflammation of the endometrium.