Introduction: This study was designed to investigate the characters of the human endometrial epithelial cells when cultured on either plastic or ECM (Extracellular Matrix) Gel surface and to study ultrastructural features of cultured cells in comparison to endometrial tissue. Material and Methods: Human endometrial tissue was obtained from patients who had undergone hysterectomy for uterine myoma or pathology of the oviduct. The tissue was divided into two parts, one part for TEM (Transmission Electron Microscopy) study and the other for culture. Uterine epithelial cells were dispersed with Collagenase type I, and cultured as a nonplarized culture in cell culture dishes. The cells of primary culture were stained with Anticytokeratin 7 to determine nature of the cells. After 5 days, the cells were trypsinized, detached from plastic surface and cultured in a dual chamber system on ECM Gel surface (Polarized culture). Finally the cells that were cultured on plastic and ECM Gel surfaces as well as endometrial tissue were prepared for TEM study. Results: Immunohistochemical staining indicated the epithelial nature of the cells cultured. Electron micrographs of the cells cultured on plastic showed flat cells with large nucleus and thin cytoplasm with few organells. In the cells, the tight junction that maintains polorized state of cell were not observed. Electron micrograph of the cells cultured on ECM Gel indicated highly polarized columnar cells with basal nucleus. These cells were attached to each other with both tight junction and desmosome. Polarized cells had features in close resembelence to cells of endometrial tissue. Conclusion: Culturing on ECM Gel causes the endometrial epithelial cell to regain their morphologic features that have been lost during culture on plastic surface.