Abstract: Objective: To analyze the maternal factors influencing the endometrial implantation window in women experiencing repeated transplant failures with assisted reproductive technology. Methods: A retrospective analysis was conducted on patient case data from the Reproductive Medicine Center of the First Affiliated Hospital of Guangxi Medical University, focusing on individuals diagnosed with repeated implantation failures and undergoing endometrial biopsy during the implantation window between April 2019 and March 2023. Patients were categorized into the receptive phase (secretory phase) group and non-receptive phase (proliferative phase) group based on the pathological findings. Maternal clinical factors impacting the transition of the endometrium to the secretory phase were analyzed. Univariate and multivariate logistic regression analysis were used to analyze the factors affecting the endometrial implantation window. Immunohistochemical staining was utilized to assess the protein expression of progesterone receptor (PR) and the receptive indicator HOXA10 in the endometrium across the two groups. Results: Compared with the secretory phase group, the serum progesterone levels in proliferative phase group were decreased, and the incidence of polycystic ovary syndrome (PCOS) and endometritis were increased (all P＜0.05). Multivariate logistic regression analysis indicated that combined with low serum progesterone levels, PCOS and endometritis were independent risk factors for the displacement of the endometrial implantation window (all P＜0.05). Immunohistochemical staining showed that the H scores of PR in the glandular epithelium and stroma of the proliferative phase group were higher than those in the secretory phase group, and the H scores in HOXA-10 in the proliferative group were lower than those in the secretory phase group (all P＜0.05). Conclusion: Maternal comorbidity with PCOS, endometritis and low serum progesterone levels are risk factors for displacement of the endometrial implantation window and decreased receptivity in individuals experiencing repeated implantation failures.