Abstract: Objective　To detect the expression of intermediate-conductance-Ca2+- activated K+ channels (IKCa1) in endometrium during peri-implantation and explore the role of IKCa1 in embryo implantation. Methods　The endometrial tissue samples of early, middle and late secretory stages and early, middle and late proliferative stages were taken respectively in 5 cases. Immunohistochemistry and quantitative PCR (qPCR) were used to detect the expression of IKCa1 mRNA and protein in endometrial tissues of different stages. Ishikawa cells were cultured in vitro and treated with different concentrations (0, 10, 20 and 30 μmol/L) of IKCa1 blocker TRAM-34. The expression of IKCa1 was detected by qPCR, cell proliferation was detected by CCK8, the cell adhesion was detected by Transwell and the expressions of EMT related proteins, E-box binding protein 1 (Zeb1) and E-cadherin were detected by Western blot assay. Results　The expression of IKCa1 was time-dependent in human endometrium. The expression level of IKCa1 was significantly higher in secretory phase than that in proliferative phase, especially in middle secretory phase. The expression of IKCa1 was inhibited by TRAM-34 in Ishikawa cells. The cell proliferation and embryo adhesion decreased, the expression of EMT marker protein E-cadherin was significantly up-regulated, and the expression of Zeb1 protein was significantly down regulated (P＜0.05). Conclusion　IKCa1 may be involved in the establishment of endometrial receptivity during peri-implantation, and may regulate embryo implantation by influencing endometrial cell proliferation and EMT.